The Chemistry of Time: Flavor Evolution and Functional Health Benefits in Aged Tea

ABSTRACT

Aged teas (dark, white, and heavily baked Oolong) undergo significant transformations during storage, yet the industry remains constrained by a lack of scientific standardization. This review dissects how storage conditions influence flavor, health benefits, and constituent changes. It further evaluates vintage prediction and accelerated aging technologies, proposing the integration of Industry 5.0 to modernize the sector. Mechanistically, aging is driven by enzymatic oxidation, nonenzymatic reactions, and microbial metabolism. The degradation of flavanols drives the reduction of bitterness and astringency, while the formation of polymeric catechins and N‐ethyl‐2‐pyrrolidinone‐substituted flavanols (EPSFs) serves as the key marker of aging. Additionally, the synergistic balance between methoxybenzenes and accumulating volatiles, such as woody/herbal compounds among others, drives the formation of the aged aroma. Regarding environmental factors, temperature, humidity, and microbial participation drive material transformation. While high‐temperature/humidity environments can accelerate transformation, they may compromise quality. In terms of health benefits, components formed after aging (e.g., EPSFs and theabrownins) demonstrate advantages in regulating gut microbiota homeostasis and improving glucolipid metabolism. Notably, aging time is not linearly positively correlated with flavor and health benefits, but rather possesses an optimal window. Although vintage prediction models have been developed, their generalization ability across batches of teas remains to be improved. In terms of accelerated aging, ultraviolet radiation and high‐voltage pulsed electric fields can induce sensory profiles closer to naturally aged tea in a shorter time than microbial inoculation and wet‐heat treatments. Concurrently, the introduction of Industry 5.0 paradigms may provide potential for addressing vintage fraud, achieving precise quality control, and promoting green development in the industry.

Abbreviations

AFB1

aflatoxin B1

Aw/a _w

water activity

CNNs

convolutional neural networks

DSS

dextran sulfate sodium

EC

epicatechin

ECG

epicatechin gallate

EGC

epigallocatechin

EGCG

epigallocatechin gallate

EPSFs

N‐ethyl‐2‐pyrrolidinone‐substituted flavanols

GA

gallic acid

GBVs

glycosidically bound volatiles

GCG

gallocatechin gallate

GO‐TAP

porphyrin‐functionalized graphene oxide

HBOT

heavily baked Oolong tea

HPEF

high‐pressure pulsed electric field

HTHH

high‐temperature and high‐humidity

IoT

Internet of Things

LDA

linear discriminant analysis

OAV

odor activity value

PCA

principal component analysis

POD

peroxidase

PTR‐TOF‐MS

proton transfer reaction time‐of‐flight mass spectrometry

QDA

quantitative descriptive analysis

RaPT

raw Pu‐erh tea

RH

relative humidity

RiPT

ripe Pu‐erh tea

TBs

theabrownins

TFs

theaflavins

TRs

thearubigins

UV‐C

ultraviolet‐C

β‐GC

β‐glucosidase

1. Introduction

While freshness is the gold standard for most agricultural commodities, specifically processed teas, including dark tea, white tea, and heavily baked Oolong tea (HBOT), defy this convention (Lv et al. 2023). These three categories exhibit unique aging potential where time acts as a catalyst for slow and complex material transformations under suitable storage conditions. This process enhances flavor profiles and health‐promoting effects. Commercially, this characteristic has fueled a rapidly expanding market where value correlates exponentially with vintage. However, the scientific transition from empirical tradition to quantifiable standardization remains fraught with ambiguity.

Recent scientific exploration has strived to keep pace with the commercial surge by decoding the material basis of flavor, health benefits, and transformation mechanisms. Regarding flavor evolution, the degradation of catechins has been identified as the primary cause for the reduction of astringency in raw Pu‐erh tea (RaPT; Zhou et al. 2020), white tea (Fan et al. 2021), and HBOT (Sun et al. 2023) during aging. Furthermore, the aromatic profile shifts from fresh and floral notes to a composite profile dominated by aged aroma accompanied by woody and medicinal nuances (Ma et al. 2025b; Huang et al. 2024). Despite these advances, the precise material basis and formation mechanisms defining the characteristic flavor (e.g., mellow and thick) remain incompletely elucidated. Similarly, while the general health benefits of tea are well‐documented (Luo et al. 2024), the dynamic evolution of these bioactivities throughout the aging process requires further clarification. On the technological front, although age authentication methods involving multiomics and artificial intelligence have proliferated (Huang et al. 2025; Zhang, Li, et al. 2025; Jin et al. 2025), the lack of robust markers has created a translation gap between laboratory achievements and practical application.

These limitations in scientific cognition directly constrain the sustainable development of the industry. The aged tea sector currently faces three critical challenges including quality deterioration due to uncontrolled storage environments, rampant vintage fraud resulting from a lack of objective standards, and the inability of long natural aging cycles to meet market demand. Consequently, the field stands at a critical crossroads necessitating a shift from experience‐dependence to scientific modernization. Existing fragmented studies are insufficient to support this systemic engineering. A comprehensive synthesis is urgently needed to integrate current knowledge and provide a theoretical foundation for the advancement of aged tea technologies.

To bridge existing knowledge gaps, this review elucidates how the processing techniques of dark tea, white tea, and HBOT lay the foundation for their aging potential. Specifically, the transformation mechanisms of key flavor and functional components, as well as the regulatory effects of aging conditions, are systematically analyzed. Additionally, this article critically assesses existing methods for age authentication and the application prospects of Industry 5.0 technologies in the aged tea industry. Finally, current research limitations are identified, and promising directions for future investigation are proposed. In summary, this review delivers four specific, actionable advances. First, we propose a processing‐driven mechanistic framework, elucidating how initial processing intensity dictates the divergent aging trajectories of volatile and nonvolatile profiles across different tea categories. Second, by synthesizing chemical and sensory data, we propose the concept of an “optimal aging window” for tea aging, challenging the myth that “older is always better.” Third, we map a paradigm shift in health efficacy, demonstrating how aging shifts the functional reliance from monomeric catechins to complex transformation products (particularly theabrownins [TBs] and EPSFs) for systemic metabolic regulation. Finally, we provide an actionable Industry 5.0 blueprint that integrates Digital Twins, Internet of Things (IoT), and blockchain technologies to achieve precise environmental control, targeted accelerated aging, and robust vintage authentication.

For this review, a systematic literature search was conducted across several authoritative databases, including Web of Science, PubMed, Google Scholar, and CNKI. Boolean operators were employed in combination with specific keywords to identify relevant studies. Key search terms included combinations such as “tea” paired with “aging,” “aged,” “vintage,” or “storage”; “aged tea” with “health” or “function”; “tea” or “food” with “artificial intelligence” or “Industry 5.0”; as well as “tea” combined with “accelerated aging” and “processing.” The inclusion criteria were strictly limited to peer‐reviewed academic articles, while studies unrelated to Pu‐erh tea, white tea, or HBOT were excluded. The references cited in this review span from 2013 to 2026, with over 50% published within the last 4 years, ensuring a comprehensive coverage of the most recent advancements in the field.

2. The Foundation of Aging Potential: Processing Techniques

2.1. Dark Tea

2.1.1. Pu‐Erh Tea

Pu‐erh tea is classified into raw (Sheng) and ripe (Shou) types based on distinct processing methods. The production involves primary processing (transforming fresh leaves into rough tea) and secondary processing (refining rough tea into refined tea). rough RaPT is produced by withering, fixation, rolling, and sun‐drying, while rough ripe Pu‐erh tea (RiPT) undergoes additional pile fermentation (Figure 1). Finished versions of both are made by sifting, blending, steam compressing, drying, and packaging their rough tea.

FIGURE 1.

Primary processing of raw Pu‐erh tea, ripe Pu‐erh tea, white tea, liupao tea, HBOT. Steps marked with a star (o tea, HBOTby sifting, blending, steam compressing, drying, and packpotential, with their typical processing parameters provided.

During primary processing, withering softens leaves under controlled conditions, enhancing membrane permeability and activating enzymes to initiate hydrolysis and oxidation, while dissipating grassy odors (Qi et al. 2024). Fixation deactivates enzymes to eliminate grassy taste and enhance aroma, requiring precise temperature control to avoid compromising aging potential (Xu et al. 2022). Rolling disrupts cell structure for efficient extraction. Sun‐drying preserves residual enzyme activity for postfermentation, reduces moisture, imparts a characteristic “sun‐dried flavor” (Lv et al. 2013). Yellowing, an optional step adapted from yellow tea, reduces bitterness and astringency in new RaPT through postfixation heating and piling, though it may diminish long‐term aging value due to phenolic degradation (Feng, Wang, et al. 2024). Steaming and compressing RaPT into cakes/bricks reduces oxygen exposure, potentially altering the internal microenvironment and moderating the aging pace dominated by oxidation and moist‐heat reactions, possibly favoring slower, more harmonious flavor development.

Pile fermentation is the defining process for RiPT (Lv et al. 2013). Using sun‐dried rough tea, it transforms through microbial, enzymatic, moist‐heat, and oxidative actions. Polyphenols oxidize, polymerize, and decompose to form RiPT's unique color, aroma, and taste. Initial moisture (40%–45%) promotes aerobic bacteria, lowering pH and accelerating oxidation; later stages are dominated by fungi producing organic acids and soluble sugars for sweetness, mellowness, and thickness. Compositionally, amino acids, tea polyphenols, GA, and catechins decrease; water‐soluble extracts and soluble pectin increase, enhancing viscosity; caffeine remains stable. Steam pressing in refining may affect volatiles, but research is limited. The complex biochemical transformations throughout pile fermentation ultimately converge to create the most defining olfactory hallmark of ripe Pu‐erh: the distinct emergence of aged aroma (Chenxiang).

2.1.2. Liupao Tea

The production of Liupao tea involves primary processing and a distinctive postfermentation stage. Primary processing includes fixation, initial rolling, piling, rerolling, and drying (Figure 1). Fixation is conducted at a relatively low temperature to preserve residual enzyme activity, facilitating later flavor transformation during fermentation (Wang et al. 2021). Rolling partially ruptures leaf cells, forming loose strips for better aeration. Piling initiates enzymatic fermentation, reducing bitterness and enhancing mellowness and sweetness. Under warm, humid conditions, chlorophyll degrades, and catechins transform into theaflavins (TFs), thearubigins (TRs), and TBs, resulting in dark yellowish‐brown leaves, dissipated grassy odors, and sticky exudate (Li, Hao et al. 2022). After piling, rerolling tightens the strips. Drying (sun or high temperature) completes primary processing, yielding Maocha.

Refining involves sorting, blending, and impurity removal, followed by microorganism‐driven postfermentation (solid‐state fermentation) and steaming. Indigenous microorganisms secrete enzymes (e.g., peroxidase and laccase) to catalyze oxidation, polymerization, degradation, and structural modifications (Cheng et al. 2021; Wang et al. 2021). These changes produce reddish‐brown leaves with a mellow, thick taste and generate volatile compounds (woody, herbal, stale notes) characteristic of Liupao tea's aged aroma (Zhang et al. 2021).

Traditional methods skip secondary microbial fermentation, steaming and compressing leaves directly into baskets for natural aging. Modern methods often include dedicated secondary fermentation via pile fermentation or steamed fermentation. During pile fermentation, leaves are regularly turned and misted to aerate, control temperature, and maintain moisture. After completion, tea is basket‐pressed, baked, and high‐temperature steamed. Steamed fermentation uses a double‐steaming/double‐compaction technique: blended tea is steamed to soften leaves, briefly dried, stacked, and tightly compressed externally to retain heat and internal oxygen, accelerating polyphenol conversion via moist‐heat. Leaves are then loosened, re‐steamed briefly, and finally basketed, baked, and steamed (Ma 2021). This efficient process eliminates unwanted microorganisms, yielding a cleaner, refined aroma.

2.2. White Tea

White tea is produced from tea plant buds or leaves through withering and drying (Zhou et al. 2023). Withering reduces leaf moisture to below 20% after 30–50 h at 15–35°C; drying further lowers moisture below 9%. Based on leaf grade, white tea is classified into Baihao Yinzhen, Baimudan, Gongmei, and Shoumei.

Withering is critical for flavor formation (Figure 1; Chen et al. 2019). Protein degradation increases free amino acids, providing substrates for enzymes like aminotransferase to generate sweet, fruity, and floral volatiles. While most glycosidically bound volatiles (GBVs) decrease, monoterpene alcohols rise, likely due to hydrolysis by β‐glucosidases, releasing free terpene alcohols. Cellular damage and water loss activate the lipoxygenase pathway, increasing fatty acid‐derived volatiles for fresh, grassy notes. During drying, low‐boiling‐point volatiles (e.g., β‐myrcene) decrease, but some GBVs increase via enzymatic glycosylation of alcohols and carbohydrates. Dehydration stress during withering causes protein degradation and biosynthesis inhibition, altering nonvolatile compounds: protein degradation is the main pathway for amino acid accumulation; flavonoid reduction relates to both oxidation and suppressed biosynthesis (Chen et al. 2020). White tea's umami and mild sweetness may stem from nucleotide/peptide accumulation and decreased astringent/bitter compounds (e.g., catechins), not solely free amino acids. Drying has minimal impact on nonvolatiles, indicating withering establishes the fundamental flavor profile. Compression significantly influences white tea flavor (Lin et al. 2025). Leaves can be compressed directly or after steaming, but steaming reduces catechins, amino acids, and sugars, diminishing freshness and increasing bitterness/astringency.

2.3. HBOT

HBOT primary processing involves key steps: withering, shaking/tumbling, pan‐firing, rolling, drying, and baking (Figure 1). It is categorized into regional styles such as Southern Fujian (e.g., Tieguanyin), Northern Fujian (e.g., Wuyi Rock tea), Guangdong (e.g., Fenghuang Dancong), and Taiwanese Oolong (e.g., Dongding). Aging suitability requires heavy roasting (90°C–120°C for 6–12 h or more); low‐temperature or short baking limits long‐term aging. Wuyi Rock tea and Tieguanyin are valued for their enhanced flavor after aging.

Flavor development occurs mainly during shaking and roasting (Liu et al. 2022). Withering‐induced dehydration promotes proteolysis and accumulation of amino acids, enhancing umami while reducing grassy aldehydes and increasing floral/fruity alcohols and esters (Zeng et al. 2025; Wang, Zhu, et al. 2025). Shaking triggers enzymatic oxidation, converting catechins to TFs to reduce astringency (Li et al. 2023). It also promotes the synthesis of compounds such as linalool, indole, and nerol. This increase is primarily attributed to the enzymatic hydrolysis of glycosidically bound precursors and further enhances the floral and fruity aromas (Wang, Zhu, et al. 2025; Liu et al. 2022). Fixation inactivates enzymes to halt oxidation and volatilizes low‐boiling‐point aldehydes (Li et al. 2023). Rolling releases cellular contents but minimally affects flavor transformation. During drying or roasting, high‐temperature processing plays a crucial role in facilitating the Maillard reaction between reducing sugars, such as glucose and fructose, and amino acids, including alanine and theanine, leading to the formation of several critical flavor compounds. Among these, alkylpyrazines, exemplified by 2‐ethyl‐3,5‐dimethylpyrazine, contribute distinct nutty and roasted flavor notes, while furans such as furfural and 5‐methylfurfural provide caramel‐like and sweet aromatic qualities (Liu et al. 2022; Chen, Liu, et al. 2025). Notably, alapyridaine, although inherently tasteless, significantly enhances the perception of umami and sweetness through synergistic effects (Feng, Yang, et al. 2024).

3. The Core of Aging: Storage Conditions, Internal Transformations, and Impact on Quality

3.1. The Trajectory of Composition and Flavor Transformation in Tea

Currently, there is no unified international or overarching national standard defining aged tea across all categories. Instead, the industry relies on specific national or group standards tailored to individual tea types. For instance, the group standard for aged Pu‐erh tea (T/TEA 002‐2019) defines it as Pu‐erh tea (both raw and ripe) stored under suitable conditions for over 5 years, characterized by the sensory attribute that its flavor improves with age. Similarly, the group standard for aged white tea (T/CSTEA 00021‐2021) specifies it as white tea aged naturally for 5 years or more in a cool, dry, and sealed environment, exhibiting a distinct aged aroma (aged aroma) or aged charm (Chenyun), typically operationalized sensorially as herbal, medicinal, and smooth descriptors. For Oolong teas, the national standard for Tieguanyin (GB/T 30357.2‐2013) defines aged Tieguanyin as products baked and stored for over 5 years, possessing a characteristic aged aroma. The group standard for aged Wuyi Rock tea (T/CSTEA 00015‐2021) requires a storage period of 4 years or more, displaying sensory traits of being aged, mellow, and smooth. Collectively, these standards indicate an industry consensus: aged tea generally refers to tea that has undergone specific storage conditions for at least 4–5 years to achieve a significantly enhanced flavor profile, although formal definitions for some categories, such as aged Liupao tea, remain absent.

In scientific research, the operationalization of aged tea diverges slightly from industry standards, typically relying on either chronological thresholds or chemical profiling. Most studies operationalize aged tea based on specific storage durations and environmental conditions, though the exact year cutoff varies depending on the sample set. For example, Ma et al. (2025a) operationalized aged tea by setting a chronological threshold of over 8 years of storage, at which point woody and aged aromas became dominant. Conversely, other studies operationalize the term based on significant shifts in the chemical profile. For instance, Ren et al. (2022) observed pronounced differences in chemical components between Pu‐erh teas stored for 1–5 years and those stored for 6–8 years, thereby operationalizing teas stored beyond the 5‐year chemical transition threshold as aged Pu‐erh tea. Having established these broad definitional frameworks, the specific trajectories of flavor and chemical evolution during the aging process can be systematically examined across different tea categories, beginning with dark tea.

3.1.1. Dark Tea

3.1.1.1. Pu‐erh Tea

RaPT, rather than RiPT, is typically subjected to extended aging to enhance its flavor quality. Current research has primarily involved comparative analyses of the flavor profiles and flavor‐active compounds in RaPT samples aged between 0 and 20 years, to elucidate the underlying transformation patterns. Overall, the flavor quality of RaPT is significantly improved after 5–8 years of aging (Zhou et al. 2020; Ren et al. 2022; Wang, Shi, et al. 2025). During this critical period, a positive correlation is observed between aging duration and flavor enhancement (Figure 2). During the initial 0–2 years of storage, the infusion color primarily displays a yellow–green hue. As storage progresses to 3–7 years, it transitions to an orange‐yellow or deep yellow appearance. Following 8 years of storage, the color develops into brown‐red or brown tones and continues to deepen with prolonged aging time (Ma et al. 2025a; Zhou et al. 2020; Chen, Long, et al. 2025; Wang, Shi, et al. 2025). In terms of taste profile, the bitterness and astringency of RaPT generally decrease with extended storage time, while umami intensity diminishes, sourness slightly increases, and mellowness and thickness are significantly enhanced (Figure 2; Ma et al. 2025a; Zhou et al. 2020; Xu, Wang, et al. 2019; Ren et al. 2022).

FIGURE 2.

Changes in dry leaves, infusion color, aroma, and taste of raw Pu‐erh tea, ripe Pu‐erh tea, Liupao tea, white tea, and HBOT during storage. The images of tea leaves and tea infusion are from Wang, Shi, et al. (2025), Xu et al. (2025), Fan et al. (2021), and Chen et al. (2013).

From a compositional perspective, the evolution of flavor compounds in RaPT during storage follows discernible patterns (Ma et al. 2025a; Zhou et al. 2020; Ren et al. 2022; Xu, Wang, et al. 2019; Chen, Long, et al. 2025; Wang, Shi, et al. 2025). Ester‐type catechins such as epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and gallocatechin gallate (GCG) progressively decrease due to hydrolysis and oxidation. Their hydrolysis yields GA, while their oxidation leads to the formation of polymerized catechins (e.g., TFs, TRs, and TBs) and flavoalkaloids. Nonester catechins also exhibit an overall declining trend. Compared with the initial storage period, the contents of EGCG and epigallocatechin (EGC) in RaPT stored for 10 years decreased by nearly 20% (Zhou et al. 2020). These changes provide a material basis for the reduction of bitterness and astringency during storage. Concurrently, amino acids undergo significant reduction, with theanine content decreasing by approximately 30% after 10 years of storage, correlating with the diminished umami taste (Zhou et al. 2020). In contrast, phenolic acids such as caffeic acid and chlorogenic acid increase markedly, likely contributing to enhanced sourness. Notably, flavoalkaloids like puerins and N‐ethyl‐2‐pyrrolidone‐substituted flavan‐3‐ols (EPSFs), formed via condensation reactions between catechins and amino acids, increase significantly. Ma et al. (2025a) suggest that EPSFs such as S‐GC‐cThea and S‐ECG‐cThea in aged RaPT may impart a kokumi taste by activating the calcium‐sensing receptor via nontargeted metabolomics and molecular docking. Kokumi is often described as a mellow and thick sensation that enhances the overall complexity and continuity of flavor. However, the exact contribution of EPSFs to kokumi and their taste properties still need to be confirmed through sensory experiments, including triangle tests or recombination with/without EPSFs. Meanwhile, alkaloids including caffeine and theobromine remain stable throughout the storage process.

Multiple studies have systematically documented the dynamic transformation of aroma profiles in RaPT during storage (Guo et al. 2023; Liu, Wang, et al. 2025; Ma et al. 2025b; Wang, Shi, et al. 2025; Tian et al. 2016; Xu, Wang, et al. 2019; Zhou et al. 2020). Consensus findings indicate that the aromatic characteristics evolve from dominant floral, fruity, and green notes in the initial stage, through woody, smoky, and nutty nuances during intermediate storage, ultimately developing characteristic aged aroma in the final phase (Figure 2). During the evolution phase of the aged aroma in RaPT, the aroma profile is anchored by a moderate stale note as its sensory background, exhibiting a dynamic sensory evolution along the aging timeline: it is initially dominated by woody notes (5–8 years), transitions into herbal medicine notes (8–10 years), and ultimately culminates in a ginseng‐like characteristic (10–15 years; Figure 2).

During the storage of RaPT, increases in both the quantitative variety and cumulative relative concentration of volatile compounds have been documented (Ma et al. 2025b). Due to variations in raw materials, storage conditions, and methodological approaches, studies on the evolution of aroma components in RaPT during aging have yielded divergent findings (Tian et al. 2016; Liu, Wang, et al. 2025; Wang, Shi, et al. 2025; Guo et al. 2023; Ma et al. 2025b). However, a consistent observation is the significant increase in methoxybenzenes, key contributors to the stale aroma, during the aging process, indicating their potential as chemical markers for distinguishing young and aged RaPT. The decline of green odor components such as (E)‐2‐octen‐1‐ol and 1‐hexanol, alongside the increase of woody note contributors like α‐pinene and D‐limonene, potentially explains the gradual replacement of green aromas by woody notes during the aging of RaPT (Guo et al. 2023).

During storage, the aroma profile of RiPT evolves from “Duiwei” (a complex scent resulting from pile fermentation, including stale, earthy, damp woody, and hay‐like notes) as well as woody and sweet aromas, toward a more pronounced aged aroma. Its taste becomes progressively more mellow and thick. The infusion color remains predominantly reddish‐brown and shows no significant change over time (Xie et al. 2015; Zhang, Huang, et al. 2024). Xie et al. (2015) observed that the content of aromatic compounds, such as 1,2,4‐trimethoxybenzene and methyl isoeugenol, decreased with prolonged storage. Terpenoids, including linalool, myrcene, and α‐terpineol, also declined over time. In contrast, ketones and esters remained relatively stable, with phytone accounting for approximately 9% of the volatile composition after 9 years of storage. Additionally, certain aldehydes, such as decanal and nonanal, as well as organic acids like linoleic acid, increased in the later stages of aging.

The dynamic changes in methoxybenzenes are particularly critical to the sensory transition of RiPT. Gao et al. (2021) reported similar trends, noting a significant decrease in methoxybenzenes. For instance, the content of 1,2,4‐trimethoxybenzene dropped from 26.23 µg/g to 8.97 µg/g. Methoxybenzenes are key contributors to the stale odor, and at high concentrations, they may impart a strong stale or musty scent. During the pile‐fermentation process, methoxybenzenes accumulate continuously, reaching a peak by the end of fermentation. As a result, freshly fermented RiPT often exhibits a pronounced stale note. However, as storage continues, the reduction in methoxybenzenes leads to a gradual weakening of the stale character, thereby reducing its masking effect on woody, floral, fruity, and sweet aromas. This transition ultimately contributes to the formation of a well‐balanced and pleasant aged aroma. Wang et al. (2017) suggested that the aroma profile of well‐aged RiPT is characterized more by aged aroma rather than a stale smell. Therefore, methoxybenzenes should not be regarded as the defining components of the aged aroma in Pu‐erh. Instead, key compounds responsible for the characteristic aged aroma include cedrol, cedrene, β‐guaiene, α‐ionone, β‐ionone, dihydroactinidiolide, benzyl acetate, and benzyl benzoate, which predominantly exhibit woody and agarwood‐like scents.

It is important to emphasize that aged aroma and stale odor (Chenwei in Chinese) represent distinct olfactory attributes that are often conflated in the literature. According to the Chinese National Standard (GB/T 14487‐2017, Tea vocabulary for sensory evaluation), aged aroma is defined as a pleasant fragrance developed through the proper aging of high‐quality tea materials, which must be free from off‐odors and musty notes. It is a blended aroma profile, potentially composed of woody, cedar‐like notes, and herbal medicine notes, along with a properly controlled intensity of stale scent. By contrast, stale odor typically refers to undesirable, unfresh odors, often resembling off‐flavors arising from lipid oxidation. Chemically, staleness is primarily characterized by high concentrations of methoxybenzenic compounds (e.g., 1,2,3‐trimethoxybenzene, 1,2,4‐trimethoxybenzene). During proper aging, the relative abundance of these compounds gradually decreases in the RiPT, while volatiles associated with woody and herbal notes accumulate and ultimately dominate to form aged aroma (Zheng, Yue, et al. 2026). But a moderate level of stale odor is essential to the overall aged aroma of RiPT (Wang, Li, et al. 2022). Thus, while methoxybenzenes should be considered as major contributors to the aged aroma, they are not the sole components involved. The volatile profile of genuine aged aroma primarily includes cedrol, cedrene, β‐guaiene, δ‐cadinene, α‐ionone, β‐ionone, and dihydroactinidiolide, alongside an appropriate, balanced proportion of methoxybenzenes (Zheng, Yue, et al. 2026). Zhao et al. (2025) further confirmed that 1,2,3‐trimethoxybenzene and certain terpenes like cedrol serve as the most influential aroma‐active markers for discriminating RPT vintages through OAV and VIP analysis.

Importantly, during the aging of RaPT, the aged aroma steadily enhances alongside the continuous increase in methoxybenzenes. This seemingly contradictory phenomenon can be explained by sensory interactions and the overall reconstruction of the flavor matrix within the context of flavor chemistry (Niu et al. 2022). Although instrumental quantitative analysis indicates that the absolute concentrations of methoxybenzenes, represented by 1,2,3‐trimethoxybenzene and 1,2,4‐trimethoxybenzene, indeed show an upward trend during the storage of RaPT, human olfactory perception is not a simple linear superposition of individual volatile compound concentrations. Furthermore, the “one‐to‐many, many‐to‐one” interaction model between olfactory receptors and odorants establishes a complex network relationship between chemical components and aroma perception (Qin, He, et al. 2025). During the long‐term aging process, alongside methoxybenzenes, other key aroma‐active compounds imparting woody, herbal, and sweet notes accumulate synchronously (Ma et al. 2025b); within the highly complex tea aroma matrix, these increasing positive aromas may exert significant masking and synergistic modifying effects on the stale odor. Due to the synergistic fusion among these compounds, the originally dull stale odor reaches a new dynamic perceptual balance with the woody and herbal notes, ultimately being comprehensively perceived as a harmonious and pleasant aged aroma (Ma et al. 2025b; Zhou, Hu, et al. 2025). Moving forward, integrating aroma recombination and omission tests with large‐scale sensomic analyses is crucial for defining the chemical foundation and precise proportions of the aged aroma, which will ultimately reveal the systematic rules of its aroma profile.

For RiPT, the fermentation process exerts a far greater influence on nonvolatile components than storage duration. As storage duration increases, the bitterness and astringency of the tea infusion diminish significantly, while the sweetness and kokumi consistently increase (Zheng, Bai, et al. 2026). Typically, a sensory equilibrium, characterized by mild bitterness and a pronounced sweet and mellow taste, is reached after approximately 10–15 years of aging. This dynamic flavor evolution, often encapsulated by the traditional belief that “the older, the better,” is fundamentally driven by distinct metabolic remodeling. On one hand, the extensive oxidative polymerization and degradation of monomeric catechins (such as EGCG) and certain flavonoids during the long‐term postfermentation process serve as the direct chemical prerequisite for the attenuation of bitter and astringent stimuli. On the other hand, the significant accumulation of lipids, including polyunsaturated fatty acids (such as α‐linolenic acid) and their hydroxylated derivatives during the later stages of aging, greatly enhances the smoothness and physical thickness of the tea infusion.

Despite these distinct sensory improvements during storage, the initial pile‐fermentation process actually exerts a far more profound influence on the overall nonvolatile chemical profile of RiPT than the aging duration. Cao et al. (2021) compared the chemical compositions of fresh raw Pu‐erh, freshly ripe Pu‐erh, and RiPT aged for 10 years. They found that, compared to raw tea, ripe tea showed increased levels of GA, acetylated amino acids, and purine/pyrimidine alkaloids, while the contents of acidic compounds, amino acids, flavonoid glycosides, and catechins decreased significantly. Importantly, the chemical profile of the 10‐year‐aged ripe tea was highly similar to that of freshly fermented ripe tea, indicating that long‐term storage induces considerably smaller changes in the overall chemical composition of ripe Pu‐erh than the fermentation process does. Similar results were reported by Wang et al. (2018), who analyzed the chemical composition of raw and RiPTs with different storage periods. They observed that the impact of fermentation on tea compounds was markedly more significant, with the differences between raw and ripe teas being far greater than those attributable to storage length. The pile fermentation of Pu‐erh tea is an active, intense, and largely irreversible biochemical process. Within a relatively short period, it drastically alters the chemical composition and structure of the tea leaves through enzymatic oxidation, microbial activity, and thermal hydration. After fermentation, the chemical constituents have undergone vigorous reactions and tend to stabilize. Thus, fermentation influences the composition of the tea far more profoundly than storage. Studies on changes in nonvolatile components during the storage of RiPT have yielded inconsistent results. Variations have been reported in the changes of major constituents such as tea polyphenols, amino acids, and alkaloids across different studies (Zou 2019; Zhang, Huang, et al. 2024; Chen, Dai, et al. 2024). It can therefore be inferred that the changes in nonvolatile components during the storage of ripe Pu‐erh are relatively limited, and the discrepancies observed across studies may stem largely from differences in raw material composition. Setting aside raw material variations, it is reasonable to hypothesize that TBs content increases during the storage of RiPT. This is because conditions conducive to TBs formation, including the presence of parental compounds (TFs, TRs, and polysaccharides), enzymes, and microorganisms, persist even after fermentation (Wang, Qiu, et al. 2022).

However, evidence suggests that the quality improvement of RaPT is not infinite as a result of aging. Jiao et al. (2024) observed that after 18 years of storage, RaPT exhibited a diminished aging aroma and reduced mellowness, while Wang, Sheng, et al. (2022) similarly reported that RaPT stored for 14 years developed off‐odors and increased sourness, thereby negatively affecting its flavor quality. This decline is likely attributed to the excessive oxidation and decomposition of key flavor compounds caused by prolonged storage; for instance, the total amino acid content in tea stored for 14 years decreased by approximately 66% compared to that stored for 3 years (Wang, Sheng, et al. 2022). Furthermore, excessively long aging cycles significantly increase the probability of quality degradation due to improper storage conditions. Given that traditional warehousing often lacks standardized quality control protocols, extended storage periods render the tea vulnerable to prolonged exposure to temperature and humidity fluctuations, making it highly susceptible to contamination by environmental off‐odors or harmful microorganisms. Untargeted metabolomic and sensory profiling revealed that RiPT reaches a state of “sensory equilibrium” at approximately 15 years of storage (Zheng, Bai, et al. 2026). At this crucial stage, water extract levels peak, and traditional quality markers balance to yield an optimal interplay of sweetness, kokumi, and mild bitterness, after which the metabolic profile enters a stabilization phase.

3.1.1.2. Liupao Tea

During the prolonged storage of Liupao tea, its taste profile evolves to become more mellow and thick, with a noticeable enhancement in sweetness. This improvement is largely attributed to the increased levels of TRs, TBs, and total soluble sugars that accumulate over time (Gan et al. 2025; Wei et al. 2015). Recent studies have elucidated that 3,4‐dimethoxytoluene and 1,2‐dimethoxybenzene are the primary contributors to the stale aroma in Liupao tea (Yang et al. 2025). Furthermore, the reduction of 3,4,5‐trimethoxytoluene has been found to drive the dissipation of “smoky” notes during the aging process. Notably, intermedeol was identified for the first time in dark tea, with its concentration increasing significantly as aging progresses. A study by Xu et al. (2025) examined the evolution of aroma characteristics in Liupao tea samples aged from 2 to 15 years under relative humidity (RH) below 60%. The aroma profile was found to undergo three distinct stages of transformation: during the early storage phase (2–6 years), floral notes diminished; in the middle stage (6–11 years), woody aromas became pronounced and musty odors disappeared; after long‐term storage (exceeding 10 years), the overall sensory quality improved markedly, with the emergence of herbal and distinct woody notes. Correspondingly, compounds contributing to woody scents, such as cedrol, α‐cedrene, and β‐cadinene, increased significantly over the storage period. Terpenes consistently dominated the volatile composition, and their relative content rose sharply to nearly 70% in the 15‐year‐aged sample, substantially higher than in other samples (approximately 30%–40%). In contrast, the relative abundances of heterocyclic compounds, aldehydes, and esters exhibited a clear declining trend as storage duration extended.

In contrast, elevated humidity conditions (70%–80% RH) drastically accelerate the aroma transformation of Liupao tea, inducing notable flavor shifts within just 6 months (Yang et al. 2025). Over the 6‐month storage period, the aroma profile shifted significantly from smoky to stale‐dominated. Earthy and sweet aroma became prominent at 4 months and at 2 and 6 months, respectively. These changes were driven directly by the dynamics of key aroma compounds: the decline in smoky resulted from a rapid reduction in the concentration of 3,4,5‐trimethoxytoluene (its odor activity value [OAV] decreased from above 1 to below 1); the emergence of an earthy character was dominated by geosmin, a microbial metabolite that increased markedly at 4 months (OAV reaching 5551.88); and the formation of a stale note was closely associated with the accumulation of compounds such as 1,2‐dimethoxybenzene and 3,4‐dimethoxytoluene. These findings indicate that under higher humidity conditions, Liupao tea can undergo aroma transformation in a relatively short time, developing a characteristic stale aroma.

3.1.2. White Tea

During storage, white tea experiences transformations in its flavor compounds, leading to corresponding changes in color, taste, and aroma. For Shoumei white tea, samples aged 1 and 3 years display slightly curled dried leaves with a yellow–brown coloration accompanied by reddish tones, while the tea infusion exhibits an orange‐yellow hue. In contrast, Shoumei tea stored for 5 and 7 years develops a reddish‐brown dried leaf appearance with bronze highlights, and the tea soup turns orange‐red. The taste profile shifts from a dominant fresh and brisk sensation in the first 1–3 years to a gradual emergence of aging charm and grain aroma after 5–7 years (Zhang, Xin, et al. 2024). For Baimudan white tea aged between 1 and 13 years under controlled conditions of 40%–70% humidity and 15–30°C, the tea infusion progressively darkens to a brownish color. Concurrently, the taste evolves with a reduction in astringency and umami, while attributes such as mellowness, smoothness, sweetness, and sourness become more pronounced (Fan et al. 2021). At the molecular level, the decline in flavonoids, tannins, and amino acids is closely linked to the reduction in astringency and umami. Meanwhile, the accumulation of phenolic acids, total organic acids, and sugars over storage time likely underpins the enhancement of sour notes.

During the storage of white tea, the contents of catechins, TFs, TRs, flavonol glycosides, and most amino acids show a decreasing trend; while the levels of total flavonoids and TBs increase; the caffeine content remains relatively stable with no significant changes (Dai et al. 2018; Ning et al. 2016; Xie et al. 2019; Chen, Dai, et al. 2024; Zhang, Xin, et al. 2024; Zhao et al. 2022; Zhou, Chen, et al. 2025). A key finding is that the accumulation of EPSFs shows a significant positive correlation with storage duration, making them a proposed reliable chemical marker for characterizing the long‐term aging of white tea. Furthermore, the dynamic conversion of glycosylated flavonols to their aglycone forms has also been observed in studies (Zhao et al. 2022).

The aroma profile of white tea undergoes significant transformations during storage. For Baimudan white tea, the aromatic characteristics shift gradually from sweet, fruity, and floral notes to herbal and aged aroma over 1–3 years of storage (Huang et al. 2024). At the molecular level, this evolution is driven by a decrease in key aroma compounds positively associated with sweet, fruity, and floral scents, such as 2‐hexenal, 2‐methyl‐2‐hepten‐6‐one, linalool, and geraniol, alongside an increase in substances linked to herbal and aged aromas, including hexanoic acid, thiophene, propanoic acid, dimethyl disulfide, and bornyl acetate. These compositional changes collectively contribute to the sequential flavor succession observed in white tea during aging. As flavor compounds evolve with storage duration, the dominant substances defining tea character vary across different stages. Zhang, Xin, et al. (2024) identified L‐tryptophan, L‐ornithine, and L‐theanine as critical components imparting a refreshing taste to Shoumei tea aged 1–3 years, whereas quercetin, rutin, and hesperidin were found to confer distinct aging charm and grain‐like aroma to samples stored for 5–7 years.

Changes in flavor compounds during white tea storage may also involve microbial activity. Wang, Wang, et al. (2023) proposed a significant correlation between the decline in catechin content and microbial processes. Their findings indicated that extended storage enriched microbial pathways related to flavonoid metabolism, with aerobic bacteria (particularly Paenibacillus and Cutibacterium) showing increased abundance and a strong negative correlation with catechin levels. This suggests that these bacteria may secrete extracellular enzymes (e.g., polyphenol oxidase and peroxidase), catalyzing the oxidation, breakdown, and conversion of key phenolic compounds like catechins.

3.1.3. HBOT

Lightly baked Oolong tea is unsuitable for aging due to its higher residual moisture content and the persistence of active enzymes, a result of its low‐temperature roasting process. These factors lead to uncontrolled oxidation during storage, causing the dissipation of aroma and the development of an undesirable “greenish off‐flavor.” In contrast, HBOT undergoes high‐temperature roasting that significantly reduces moisture content, deactivates most enzymes, and stabilizes the tea's constitution. This stability lays the foundation for a subsequent slow and controlled oxidation and aging process, which gradually develops a smoother, mellower taste and stable aromatic notes such as a distinctive aged fragrance.

During storage, the sensory quality of HBOT generally evolves as follows: in terms of taste, astringency and bitterness significantly diminish while sourness gradually intensifies, leading to a mellow palate; in terms of aroma, the fresh floral and grassy notes fade, transforming into a complex profile dominated by aged aroma and woody notes complemented by honeyed sweetness; the infusion color also deepens from a bright golden‐yellow to orange‐red or reddish‐brown. From a compositional perspective, the contents of nongalloylated catechins, TFs, flavonols, and their glycosides gradually decline over time, while the levels of numerous fatty acids and organic acids increase (Sun et al. 2023). However, after excessively long storage (25 years), flavor and bioactive compounds such as chlorogenic acid, theanine, γ‐aminobutyric acid, and theophylline actually decrease, indicating that extended storage does not necessarily equate to improved quality (Hong et al. 2021). With extended storage, woody aroma components such as (6,6‐dimethylbicyclo[3.1.1]hept‐2‐en‐2‐yl)methanol and 3,5,5‐trimethylcyclohex‐2‐en‐1‐one gradually increase (Zhang et al. 2023). Concurrently, floral and fruity aroma compounds including 2‐(4‐methylcyclohex‐3‐en‐1‐yl)propan‐2‐yl acetate, 2‐[(1S)‐4‐methylcyclohex‐3‐en‐1‐yl]propan‐2‐ol, and ethyl 3‐(furan‐2‐yl)propanoate accumulate over the years, collectively contributing to the complex woody, floral, and fruity aroma profile of aged tea.

Prestorage processing, particularly baking, fundamentally dictates the available substrate pool for subsequent aging. Chen et al. (2013) demonstrated that high‐temperature baking at 120–140°C significantly reduced the phenolic compounds of Tieguanyin tea immediately, but increased the content of GA, with no significant changes in phenolic compounds or tea color observed over 20 years of storage. In contrast, hydrocarbon volatiles remained stable during baking but decreased substantially during long‐term storage, whereas characteristic flavor compounds like substituted benzaldehydes were formed. These findings indicate that both baking and aging collectively shape the quality of aged Oolong tea: baking dominates the initial transformation of phenolic compounds, while extended storage primarily drives the evolution of volatile components.

As an intensive thermal process, heavily baking provides sufficient energy to drive vigorous chemical reactions such as pyrolysis, isomerization, and degradation. The formation of GA and GCG through the partial decomposition and isomerization of esterified catechins (e.g., EGCG) under high temperatures was confirmed in this study (Chen et al. 2013). These transformations are largely completed during baking, resulting in a new, relatively stable phenolic composition. Subsequent storage at ambient temperature for 5–20 years constitutes a mild and prolonged process with energy inputs insufficient to reactivate high‐temperature‐driven reactions. Thus, phenolic compounds remain chemically inert under these conditions without undergoing further large‐scale transformation or degradation. Meanwhile, certain nonvolatile compounds, such as pyrrole derivatives and substituted benzaldehydes formed during baking, may engage in slow chemical reactions with pre‐existing volatile compounds throughout the storage period. Additionally, the large quantities of GA resulting from high‐temperature baking supply the necessary precursors for the continuous development of aroma. This differential reactivity explains the divergent evolutionary pathways between nonvolatile and volatile components during postbaking storage. However, contrasting results were reported by Peng et al. (2022), who investigated the effect of baking on the quality of Foshou Oolong tea roasted at 90–100°C and stored for 5–10 years. Their targeted metabolomic study showed increased levels of EPSFs, flavone C‐glycosides, GA, and most lipids after baking and storage, whereas cis‐flavanols, alkaloids, flavonol O‐glycosides, and most amino acids decreased. These findings partially diverge from those of Chen et al. (2013), likely due to the lower baking temperature applied in Peng et al.’s (2022) study, which resulted in incomplete transformation of nonvolatile compounds, allowing further modifications to occur during extended storage.

3.2. Potential Mechanisms of Compositional Changes During Aging

The transformation mechanisms of aroma components during the storage process were proposed. The aroma transformation during the aging of RaPT primarily involves enzymatic (possibly dominated by microbial enzymes) and nonenzymatic oxidation reactions. Methylation reactions are key reactions in the formation of characteristic aromas in aged RaPT. Methoxybenzenes can be synthesized from GA via methylation reactions mediated by microbial activity (Li et al. 2024; Lv et al. 2012). During methylation, hydrogen atoms in the hydroxyl groups of GA are substituted by methyl groups, leading to the production of these compounds. The formation of methoxybenzenes and their derivatives is primarily regulated by methyltransferase, an enzyme that governs methylation processes involved in the synthesis, transport, and degradation of secondary metabolites. Furthermore, metagenomic studies have shown a co‐occurrence where methyltransferase in RiPT during postfermentation is predominantly associated with Pseudomonas, Aspergillus, Achromobacter, and Sugiyamaella (Li et al. 2018). However, the microbial communities responsible for methoxybenzene formation during the storage of RaPT remain unclear. Furthermore, recent studies postulate that methylphenols serve as crucial intermediates in the generation of methylated aroma compounds (Wang et al. 2026). Concurrently, 2,4,6‐tri‐tert‐butylphenol, 2,5‐di‐tert‐butylphenol, and butylated hydroxytoluene (BHT) have been identified as vital upstream precursors for the formation of these methylphenols. Moreover, pathway network analysis reveals that alongside known routes, caffeine metabolism, toluene degradation, and naphthalene degradation pathways may supply the essential methyl group precursors for methylation reactions during the aging process of RiPT.

In addition to methylation, the degradation of carotenoids and fatty acids significantly alters the aroma profile. α‐Ionone is primarily derived from α‐carotene, whereas β‐ionone originates mainly from β‐carotene. Both α‐ionone and β‐ionone can be generated through enzymatic reactions or nonenzymatic degradation (Ho et al. 2015). Nonenzymatic degradation typically involves photo‐oxidation, spontaneous oxidation, and thermal degradation. Dihydro‐β‐ionone is largely formed through the biotransformation of glycosides and β‐ionone during microbial fermentation (Ho et al. 2015). α‐Ionone and β‐ionone contribute predominantly to floral and fruity aromas. Their concentrations decrease during the storage of RaPT, aligning with the observed reduction in floral and fruity notes over time. Aldehydes serve as key contributors to the “green” and “grassy” scent profiles (Pang et al. 2019). Most aldehydes are formed through the oxidation of fatty acids in tea leaves, mainly via two pathways (free radical oxidation and enzymatic oxidation). Free radical oxidation refers to the process triggered by radical‐involved reactions such as natural oxidation, photo‐oxidation, or thermal oxidation. In contrast, enzymatic oxidation denotes fatty acid oxidation mediated by lipoxygenase, which represents the primary pathway for aldehyde formation in tea leaves (Ho et al. 2015). For instance, n‐hexanal is produced when lipoxygenase oxidizes α‐linolenic acid and linoleic acid to lipid peroxides, which are subsequently cleaved by hydroperoxide lyase to form six‐carbon aldehydes. Nonanal and heptanal are derived from oleic acid and palmitoleic acid, respectively (Ho et al. 2015). Additionally, (E,E)‐2,4‐heptadienal and (E,Z)‐2,6‐nonadienal are also generated from fatty acid oxidation. Moreover, aromatic aldehydes can be formed via Strecker degradation between amino acids and carbonyl compounds during tea fermentation (Lv et al. 2014).

Furthermore, microbial communities act as crucial drivers in these dynamic aroma changes, moving beyond mere co‐occurrence (Table S1). Wang, Shi, et al. (2025) found that in aged RaPT, Cyanobacteria and Firmicutes showed significant positive correlations with multiple key aroma compounds, including 3‐methyl butanal, (E,E)‐2,4‐heptadienal, 1‐octen‐3‐one, 2‐pentylfuran, and (Z)‐4‐heptenal. Meanwhile, Aspergillus demonstrated a significant positive correlation with n‐nonanal‐M. Aspergillus species are known to produce various enzymes, such as proteases, tannases, and hydrolytic enzymes, which play crucial roles in the transformation of tea quality. Their metabolic activities have been associated with the formation of volatile compounds contributing to floral, fruity, and minty aromas. Furthermore, fungal taxa including Ascomycota, Basidiomycota, Cladosporium, and Penicillium were positively correlated with the content of (E,E)‐2,4‐heptadienal and (Z)‐4‐heptenal. Given that fungi generally grow under lower water activity (Aw) conditions (Rifna et al. 2022), it is highly plausible that they participate actively in the transformation of aroma constituents during the extended storage of RaPT. Recent studies also highlight that the interactions between intrinsic tea chemistry and dominant fungi play a decisive role in shaping the specific quality attributes of dark teas, such as Hei brick tea (Guo et al. 2025). Of note, direct evidence regarding the contribution of microorganisms to aroma formation during tea aging has also been observed. Storage conditions withAwexceeding 0.60 have been shown to enrich specific fungal genera, including Papiliotrema, Hannaella, and Toxicocladosporium (Ma et al. 2025b). The abundance of these core fungal taxa exhibits a significant positive correlation with the accumulation of aging‐characteristic aroma components, particularly terpenoids such as linalool, linalool oxides, α‐terpineol, and cedrol.

Providing ex vivo/enzymatic plausibility, mechanistic investigations have further confirmed that the core strain Papiliotrema flavescens RPT, isolated from aged RaPT, maintains metabolic activity under storage environments and is capable of secreting β‐glucosidase (β‐GC) and peroxidase (POD). Crucially, microbial‐derived β‐GC plays a pivotal role in this process; it catalyzes the hydrolysis of glycosidic precursors within the tea matrix, liberating bound volatile aglycones (e.g., linalool and methyl salicylate), thereby directly facilitating the development of aged and medicinal flavor characteristics. Furthermore, at elevated water activities, basidiomycetous yeasts may utilize acetyl‐CoA via the mevalonate pathway to generate terpenoid precursors, subsequently promoting the biosynthesis or release of monoterpenes and sesquiterpenes. Collectively, these findings suggest that modulating Aw to activate specific microbial enzymatic metabolism represents a critical transformation mechanism driving the de novo synthesis or liberation of aroma compounds during tea aging.

During storage, ester‐type catechins undergo hydrolysis, yielding GA and other compounds (Figure 3A). This transformation is fundamentally driven by the cleavage of ester bonds. Elevated temperatures or the presence of specific enzymes can accelerate the reaction rate. During tea storage, where temperature and humidity are generally lower and microbial and enzymatic activities are minimal, the same series of reactions proceed at a considerably slower pace. Nevertheless, over years of storage, the cumulative changes in compound composition and concentration remain significant. Mechanistically, polymerized catechins are generated through the following process (Figure 3B). At the initial phase, catechol‐type catechins undergo oxidation catalyzed by polyphenol oxidase, leading to the formation of o‐quinone intermediates. These intermediates then participate in selective coupling with pyrogallol‐type catechins via enzymatic or redox‐mediated pathways. The adducts produced further engage in nonenzymatic condensation with additional pyrogallol‐type quinones, progressing through oxidation and decarboxylation steps to ultimately yield TFs featuring a benzotropolone skeleton (Zhang, Wang, et al. 2025). The o‐quinone intermediates may also polymerize into biphenolquinones and dehydrotheasinensins, which subsequently undergo oxidation or disproportionation to generate theasinensins. Both TFs and theasinensins can be oxidized to form TRs (Zhu et al. 2021). TBs are generated primarily through two pathways: one involves the polymerization of TRs with caffeine and macromolecules (e.g., polysaccharides and proteins); the other, considered the dominant route, entails the direct oxidation and polymerization of o‐quinones into TBs (Chen, Wang, et al. 2024).

FIGURE 3.

The underlying transformation mechanisms of nonvolatile constituents in the tea aging process. (A) Degradation of catechins. (B) Formation of N‐ethyl‐2‐pyrrolidinone‐substituted catechins. (C) Formation of theaflavins, thearubigins, and theabrownins.

Although the evolutionary pathway of tea pigments is structurally similar during initial tea manufacturing and subsequent long‐term storage, the relative contributions of specific reactions and their underlying driving forces differ fundamentally. During manufacturing (e.g., pile fermentation of Pu‐erh tea), the environment is characterized by elevated temperatures and high humidity. Under these conditions, endogenous polyphenol oxidases released from disrupted cell walls, alongside extracellular enzymes secreted by a blooming microbial community (fungi and bacteria), are exceptionally active. Consequently, vigorous enzymatic oxidation plays the absolute dominant role. Pigment conversion occurs rapidly over days or weeks, leading to a swift accumulation of TBs.

The presence of TFs and TRs in aged RaPT, white tea, and HBOT is largely inherited from the initial manufacturing processes‐such as slight enzymatic oxidation during prolonged withering (white tea), residual oxidation after rolling (RaPT), or thermal oxidation during roasting (HBOT). During the long‐term storage of dry tea, the environment is maintained at low Aw (typically < 0.60) and relatively low temperatures. In such restricted environments, endogenous enzymatic activities are severely suppressed, and microbial metabolism remains largely dormant. Consequently, substantial de novo synthesis of TFs and TRs during aging is minimal. Instead, pigment transformation primarily relies on extremely slow nonenzymatic auto‐oxidation and chemical coupling. The TFs and TRs inherited from processing act as transient intermediates that gradually polymerize to form TBs. Only when the ambient Aw marginally increases (e.g., Aw > 0.60) does the metabolic activity of specific xerophilic storage fungi (such as P. flavescens RPT) become activated, providing a modest enzymatic contribution to pigment conversion (Ma et al. 2025b). This thermodynamic and kinetic bottleneck explains why natural aging is a protracted, gradual process unfolding over years or even decades. Ultimately, this leads to a steady net accumulation of TBs and a gradual decline or stabilization of inherited TFs and TRs, rather than a strong continuous accrual of these intermediate pigments.

EPSFs are formed through reactions between theanine and catechins, and are markers of most aged tea (Table S2). Figure 3C shows a proposed formation mechanism for EPSFs (N‐ethyl‐2‐pyrrolidinone‐substituted catechins); detailed structural information on various EPSFs can be found in the comprehensive review by Gao et al. (2025). In white tea, Oolong tea, and pu‐erh tea, EPSFs all show an increasing trend. In white tea, the total EPSFs increased significantly from approximately 0.10 mg/g in fresh tea to 2.07 mg/g after 10 years of aging (Lin, Zhang, et al. 2024). In Oolong tea, the total EPSFs rose from an initial 0.10 mg/g to 1.30, 6.15, and 8.48 mg/g after 5, 10, and 15 years of aging, respectively (Peng et al. 2022). In RaPT, although the content of EPSFs increases, its levels have not been accurately determined using targeted metabolomics. The proposed mechanism begins with the degradation of theanine to the corresponding Strecker aldehyde, which subsequently undergoes spontaneous cyclization to form 1‐ethyl‐5‐hydroxy‐2‐pyrrolidinone. This intermediate then reacts with catechins to yield EPSFs (Dai et al. 2018). Furthermore, the carbon atom in the pyrrolidine ring that connects to the catechin moiety is chiral, resulting in EPSFs existing in both R and S configurations. Specifically: reaction of EGCG with theanine produces both (S)‐8‐C‐N‐ethyl‐2‐pyrrolidinone‐substituted EGCG and its (R)‐configured analogue; ECG yields (R)‐8‐C‐N‐ethyl‐2‐pyrrolidinone‐ECG; EGC forms both the (S) and (R) forms of 8‐C‐N‐ethyl‐2‐pyrrolidinone‐EGC; and EC generates the corresponding (S) and (R) configured products (Dai et al. 2018; Peng et al. 2022).

While nontargeted metabolomics has been widely employed to screen for aging markers, establishing standardized analytical protocols for EPSFs remains challenging due to their low natural abundance and the highly complex tea matrix (Gao et al. 2025). Currently, targeted quantification using liquid chromatography coupled with high‐resolution mass spectrometry or tandem mass spectrometry operating in multiple reaction monitoring mode is considered the analytical best practice to effectively mitigate matrix ion suppression. Furthermore, since EPSFs naturally exist as chiral mixtures (R‐ and S‐configurations), MS alone is insufficient for absolute stereochemical assignment; thus, integrating nuclear magnetic resonance and circular dichroism spectroscopy is indispensable for rigorous structural elucidation. During the qualitative and quantitative analysis of EPSFs, several known interferences must be critically addressed. The primary interference arises from the severe coelution of structural isomers. EPSFs comprise various regioisomers (e.g., substitutions occurring at either the C‐8 or C‐6 position of the catechin A‐ring) and chiral enantiomers, which are exceedingly difficult to separate on conventional reversed‐phase columns, often leading to quantification inaccuracies. Another significant confounding factor is structural instability during extraction and purification. For instance, certain EPSF subtypes, such as catechin spiro‐γ‐lactones, are highly susceptible to spontaneous cis‐to‐trans skeleton transformation in their pure states or under specific extraction conditions, posing immense challenges for accurate identification and absolute quantification.

3.3. The Science of Storage: Impact of Environmental Factors

The transformation of flavor and health efficacy during tea aging results from a series of slow and complex enzymatic oxidations and nonenzymatic chemical reactions involving its chemical constituents under the influence of specific environmental factors. This transformation process is primarily regulated by key environmental variables, including temperature, humidity, oxygen, and light exposure.

Suitable temperature serves as the driving force for microbial activity and chemical reactions. Excessively high temperatures can drastically accelerate most chemical reactions, potentially disrupting the activity of metabolic enzymes and leading to the overly rapid progression of certain reactions. This can result in the development of undesirable off‐flavors. For example, when stored under natural humidity conditions for 3 or 6 months, White Peony tea kept at 35°C showed a significantly accelerated degradation of total polyphenols and catechins compared to storage at 15°C, accompanied by a markedly lower taste score (Wang, Qin, et al. 2025). Conversely, excessively low temperatures significantly inhibit microbial and enzymatic activity, causing the aging process to nearly stagnate and hindering the favorable development of its flavor profile. Currently, studies on the effects of temperature on quality changes during the storage of dark tea and HBOT remain limited and warrant further investigation.

Moisture acts as the essential medium for biochemical reactions and is a prerequisite for microbial growth and reproduction. Tea leaves absorb moisture from the surrounding air. High moisture content promotes the hydrolytic degradation of compounds and increases the risk of microbial contamination. Excessively high humidity can lead to harmful mold growth in the tea, producing toxic harmful substances and completely compromising its quality. Storage of white tea at 25°C for 3 or 6 months under 60% RH led to a significantly higher degradation of total polyphenols compared to storage at 40% RH, accompanied by a markedly lower taste score (Wang, Qin, et al. 2025). According to the Chinese National Standard (GB/T 30375‐2013, Tea Storage), Oolong, white, and dark teas are recommended to be stored below 25°C, with Oolong and white teas kept at a RH below 50% and Dark teas below 70% to preserve their flavor quality; however, to promote their transformation, local standards specify different conditions: for Pu‐erh tea, the Dongguan City Standard (T/DGAS 022‐2021) permits storage at temperatures not exceeding 32°C and 75% RH; and for Anhua Dark tea, the Hunan Provincial Standard (DB43/T 1736‐2020) recommends storage at temperatures not exceeding 35°C and 75% RH; for white tea, the Fujian Provincial Standard (DB35/T 1896‐2020) allows storage at up to 35°C and 50% RH.

Regarding natural storage environments, significant differences in taste and chemical composition were observed in RaPT stored for extended periods in Dongguan City (characterized by a hot and humid climate) compared to Kunming City (characterized by a cold and dry climate; Zhou et al. 2020). In samples aged in Dongguan, the decline in ester‐type catechins (e.g., ECG, EGCG, GCG) and amino acids occurred more rapidly than in those aged in Kunming, while the levels of gallic acid (GA), quercetin, and kaempferol increased significantly. Xu, Wang, et al. (2019) compared the flavor quality and chemical changes in RaPT stored in Guangzhou (a hot and humid environment) and Urumqi (a dry and cold environment). They noted that the teas stored in Guangzhou underwent more pronounced changes in taste: umami and astringency decreased significantly over time, particularly after 5 years, accompanied by a substantial reduction in amino acids, catechins, and flavonoid glycosides. These findings indicate that high temperature and humidity accelerate the transformation of flavor‐related compounds in RaPT, leading to a more rapid evolution of its sensory characteristics.

However, recent studies have highlighted the profound impact of extreme high‐temperature and high‐humidity (HTHH) conditions on accelerating the chemical transformation of RaPT (Qin, Gao, et al. 2025). For instance, exposing RaPT to an HTHH environment (80°C and 80% RH) for just 5 days drastically alters its chemical profile and sensory attributes. Under these accelerated conditions, the content of tea polyphenols rapidly degrades from 4.47% to 1.15%. Conversely, TBs increase significantly from 1.14% to 2.56%, which directly drives a rapid darkening of the infusion color, characterized by significantly increased redness and yellowness. Concurrently, the volatile profile undergoes a massive shift under HTHH treatment. Floral and fruity compounds, such as linalool and (+)‐dipentene, decrease rapidly. They are replaced by intense roasted, woody, and distinctively “burnt” and “caramel” aromas. This unique aroma evolution is mechanistically driven by intense Maillard reactions, which is evidenced by a dramatic increase in 5‐hydroxymethylfurfural from 1.34 mg/kg to 4.14 mg/kg. Furthermore, the synergy of the Maillard reaction, lipid oxidation, and the enzymatic degradation of lignin leads to the accumulation of key odorants, including 5‐methyl‐2‐furancarboxaldehyde (caramel), tea pyrrole (burnt), 1‐octen‐3‐one (mushroom), and guaiacol (burnt).

While HTHH technology rapidly converges the color and certain mellow characteristics of raw tea toward those of traditionally fermented RiPT, it fundamentally diverts the aroma trajectory by introducing thermally driven burnt and caramel notes. Based on these findings, a comparison between natural hot‐and‐humid aging and artificial extreme HTHH aging reveals that although extreme conditions can drive the tea's color and certain components toward aged characteristics within merely a few days (e.g., the rapid degradation of polyphenols and the massive accumulation of TBs), this significantly diverts the evolution of volatile profiles from their natural aging trajectory. Excessive HTHH environments induce intense Maillard reactions and lipid oxidation, leading to the rapid depletion of floral and fruity volatiles such as linalool. This is accompanied by the massive generation of characteristic compounds exhibiting “burnt” and “caramel” odors, including 5‐methyl‐2‐furancarboxaldehyde and guaiacol. Collectively, this evidence indicates that while moderately elevating temperature and humidity can effectively promote tea aging, there exists a distinct threshold for these environmental parameters. Once this threshold is breached, it leads to a severe deviation in aging trajectories, such as the polymerization of water‐soluble pigments and the evolution of aroma.

Given that high humidity significantly accelerates tea aging, it is frequently employed in storage practices; however, this approach introduces profound safety risks. During storage, tea is susceptible to infection by toxigenic fungi such as Aspergillus flavus, and high‐humidity environments are particularly conducive to their growth and metabolism (Yu and Wu 2022). Li et al. (2017) inoculated raw and RiPT with an A. flavus YM 31882 strain and stored them under various conditions (30°C with 80% RH, 30°C with 90% RH, and ambient room conditions) for 28 days. The results revealed that all samples inoculated with the A. flavus strain developed fungal spores, and the count of A. flavus was significantly higher under HTHH conditions compared to ambient room conditions, demonstrating that HTHH storage inevitably leads to tea molding. Paradoxically, mycotoxin analyses of samples taken on Days 7, 14, 21, and 28 yielded a 0% detection rate for aflatoxins B1, B2, G1, and G2. This indicates that even when Pu‐erh tea undergoes severe molding under ambient or extreme humid conditions, it does not necessarily accumulate carcinogenic aflatoxins. Although the exact mechanism remains unelucidated, it is hypothesized that the bioactive compounds intrinsic to Pu‐erh tea may inhibit key enzymes involved in aflatoxin biosynthesis. This is supported by previous findings demonstrating the potent inhibitory effects of GA, quercetin, and overall tea extracts on aflatoxin production (Li et al. 2015; Lu et al. 2015). Nevertheless, this absence of aflatoxins does not imply that the safety of humid‐aged tea is guaranteed. Because this specific study solely screened for aflatoxins, the potential generation of other uncharacterized mycotoxins or harmful metabolites under high‐humidity conditions remains a critical area requiring further comprehensive investigation.

To effectively address these risks, the latest advancements emphasize the prospects of machine learning‐assisted multiomics techniques, which significantly enhance both the detection accuracy of mycotoxins and overall safety monitoring during tea processing and storage (Okoye et al. 2025). Effective risk management requires a dual approach of rigorous screening and proactive remediation. For screening, liquid chromatography‐tandem mass spectrometry has emerged as the gold standard, offering the necessary sensitivity to simultaneously detect multiple mycotoxins within complex, pigment‐rich tea matrices (Zhou et al. 2022). Regarding prevention and remediation, maintaining the Aw strictly below the critical threshold of 0.65–0.70 remains the primary physical defense (Table S3). Furthermore, recent scientific advancements highlight the promising potential of biological control (biocontrol) as a remediation strategy. For instance, Zhao et al. (2020) demonstrated that probiotic fungal strains indigenous to fermented teas, specifically Eurotium cristatum, competitively inhibit the radial growth of aflatoxigenic A. flavus. More importantly, cell‐free supernatants of E. cristatum facilitate the effective degradation of AFB1 into significantly less toxic compounds lacking the carcinogenic lactone ring. Implementing these advanced screening protocols and biological remediation strategies is crucial for ensuring the absolute safety of aged teas in international markets.

Oxygen participates in the oxidation processes of many substances within tea, such as catechins, polymeric catechins, vitamin C, lipids, carotenoids, and alcohols. The role of oxygen in tea storage exhibits a distinct dichotomy depending on the tea category. For green tea, oxygen acts as a primary catalyst for quality deterioration. Recent studies demonstrate that exposure to oxygen accelerates lipid oxidation and the thermal degradation of carotenoids, leading to the rapid accumulation of ketones and alcohols that impart undesirable stale off‐odors (Wang, Xu, et al. 2025). Conversely, for aging‐capable teas like Pu‐erh and white tea, a controlled presence of oxygen is an indispensable driving force. Oxygen not only sustains the aerobic microbial communities essential for postfermentation but also continuously drives the slow, nonenzymatic auto‐oxidation of monomeric catechins into complex polymeric pigments (e.g., TBs), which fundamentally shapes the taste and aroma of aged teas. Therefore, for aging‐capable teas, where quality transformation is desired, the use of oxygen‐permeable packaging materials and regular airing of the storage environment is recommended to facilitate these necessary oxidative changes. Therefore, for tea undergoing aging, vacuum packaging, modified atmosphere packaging, completely sealed packaging, and the use of oxygen scavengers are not recommended, as they can drastically reduce, even below 0.1%, the oxygen level inside the package (Dey and Neogi 2019). This structured approach to controlling the storage environment is crucial for guiding the aging process toward the development of a high‐quality tea.

Furthermore, light, particularly ultraviolet radiation, can induce profound photo‐oxidation. It may degrade chlorophyll and various aromatic substances, leading to quality deterioration (Ho et al. 2015). Consequently, prolonged light exposure typically drives the excessive oxidation of the tea's intrinsic components, resulting in severe quality degradation. However, emerging research suggests that a short‐term light exposure may actually improve certain quality attributes and selectively accelerate the aging process (Zhang, Feng, et al. 2025).

Current research tends to support the hypothesis that microorganisms may participate in the transformation of substances during tea aging, though direct proof is still rare. Li, Wu, et al. (2022) studied RiPT stored for 180 and 360 days postfermentation under conditions of 25–30°C, > 10% RH, and about 6% tea moisture. While Rasamsonia emersonii and Thermomyces lanuginosus dominated late fermentation, Blastobotrys adeninivorans became predominant during storage. Total fungal abundance (based on qPCR copy numbers) declined, whereas bacteria peaked at 360 days, exceeding fermentation levels. Wang, Shi, et al. (2025) examined RaPT stored for 14 years (2009–2023) at 40%–70% RH and 20–25°C. Early‐dominant bacteria (e.g., Bacillus and Clostridium) nearly disappeared in later stages, while Aspergillus persisted as the dominant fungus. Microbial abundance correlated significantly with flavor components. From the perspective of microbial growth conditions, the internal components of tea cakes can provide necessary nutrients for microorganisms (Zhao et al. 2019). Most microorganisms thrive at 25–40°C, aligning with tea storage (18–30°C). Although bacteria generally require Aw > 0.9, and fungi need a _w ≥ 0.78, xerotolerant species like Aspergillus survive at a _w < 0.75 in dry storage (Tapia et al. 2020; Rifna et al. 2022). Thus, tea may offer a microenvironment where such microbes secrete extracellular enzymes (e.g., polyphenol oxidase, peroxidase) to oxidize and transform catechins and other flavor compounds. Despite weak metabolic activity under dry conditions, prolonged storage (years to decades) may allow slow microbial processes to gradually alter tea composition. Correlations between microbial shifts and chemical changes in Liupao and white teas further support potential microbial roles in aging (Xu et al. 2025; Gan et al. 2025; Wang, Wang, et al. 2023). As previously discussed, specific environmental conditions (Aw > 0.6) can activate xerophilic fungi like P. flavescens RPT to drive flavor formation via enzymatic pathways (Ma, Xu, et al. 2025), demonstrating that controlled environments directly harness microbial metabolism.

Significantly, their work establishes a valuable paradigm for investigating microbial roles in tea aging. Following the identification of core functional microbiota via multiomics screening, the key strain was isolated. By testing this strain in both simulated infusions and sterile storage systems, its causal contribution to flavor transformation through specific enzymatic activities were directly confirmed. Nevertheless, future research should employ more precise methodological approaches to further elucidate the complex biochemical network of aging. Stable Isotope Probing with ¹³C‐ or ¹⁵N‐labeled precursors can track isotope flow into microbial nucleic acids and metabolites, thereby directly linking active taxa to atomic‐level substrate transformations. Furthermore, integrating functional omics with gene‐editing technologies, such as CRISPR‐Cas9, enables the characterization of key enzymes. By constructing knockout or overexpression strains, researchers can pinpoint the molecular mechanisms of flavor formation, providing a theoretical basis for targeted regulation to accelerate aging and enhance tea quality.

While advanced molecular tools hold promise for future mechanistic discoveries, current industry practices require immediate, actionable macroenvironmental control strategies. To translate these theoretical insights of environmental factors into industrial practice, we propose a comprehensive “Do/Don't” checklist for warehouse management (Table S3). This checklist provides standardizable guidelines for critical control points such as shelving, airflow, and moisture monitoring to mitigate risks like localized Aw spikes and flavor tainting.

3.4. Shift in Health Benefits

During the aging process of tea, chemical conversions occur, which significantly shape the health efficacy of the final product. Oxidative stress represents a fundamental pathological mechanism in numerous diseases. However, studies have demonstrated a declining trend in the in vitro antioxidant activity of white tea with extended aging duration (Figure 4A; Xu, Chen, et al. 2019; Wang, Wang, et al. 2023; Wang et al. 2024). This may be related to the reduction in polyphenol content during the storage of white tea. A similar reduction was observed in the in vitro inhibitory effects on key enzymes associated with Type II diabetes, namely, α‐amylase and α‐glucosidase. In contrast, in vivo studies provide an alternative perspective on the health‐promoting effects of aged white tea (Figure 4B). Lin, Dai, et al. (2024) compared the efficacy of new white tea and tea aged for 10 years in alleviating colitis in mice. Their results indicated that the 10‐year‐aged white tea conferred superior protective effects, potentially mediated by suppressing Bacteroides and Escherichia–Shigella populations while promoting the microbial conversion of primary bile acids to secondary bile acids, the latter being known for their anti‐inflammatory properties (Sinha et al. 2020). Interestingly, targeted metabolomics revealed that although the aged tea contained lower levels of flavanols, dimeric catechins, and amino acids compared to its fresh counterpart, it was enriched with EPSFs, theobromine, and (−)‐epigallocatechin‐3‐(3″‐O‐methyl) gallate. EPSFs, recognized as characteristic flavor compounds in aged teas, have demonstrated anti‐inflammatory activity (Gao et al. 2025), which may underlie the enhanced efficacy of the 10‐year‐aged tea.

FIGURE 4.

Changes in the health benefits of tea during the aging process. (A) Changes in the in vitro antioxidant activity and inhibitory effects on α‐amylase and α‐glucosidase of tea. (B) Effects and mechanisms of aged tea in ameliorating colitis. (C) Effects and mechanisms of aged tea on improving glucose and lipid metabolism.

Although aged Oolong tea exhibits a notable reduction in active constituents such as catechins and amino acids, it demonstrates considerable bioactivity in murine models (Figure 4C). Zeng et al. (2024) studied Oolong teas of different storage years (2001, 2011, 2020) in Type 2 diabetes murine models. The aged teas significantly improved dyslipidemia, insulin resistance, and hepatic steatosis in db/db mice through multiple pathways, including activating the hepatic INSR/IRS/PI3K/AKT/GSK‐3β/GYS glycogenesis pathway and regulating gut microbiota. The 2011 vintage showed the strongest overall efficacy, while the 2001 vintage best suppressed ectopic lipid deposition, and the 2020 vintage most effectively improved insulin sensitivity. TB content increased notably with extended storage, indicating its potential contribution to the bioactivity. Although aged Oolong tea alleviates intestinal inflammation in mice, excessive storage may reduce this effect. Wu et al. (2024) compared the anticolitis effects of fresh Oolong tea with teas aged 10, 20, and 30 years in mice. Their results indicated that Oolong tea alleviated colitis by modulating oxidative stress and inflammatory cytokines, upregulating intestinal tight junction proteins, and partially restoring gut microbial homeostasis. The 10‐year‐aged tea performed most effectively, whereas the 30‐year‐aged tea was significantly less potent in suppressing inflammation. Compared to fresh tea, the 10‐year‐aged Oolong tea contained lower levels of catechins but higher levels of total TFs, which may contribute to its enhanced efficacy against colitis. Additionally, uncharacterized constituents likely also play a role. Yuan et al. (2018) reported that aged Oolong tea significantly suppressed body weight gain, adipose tissue expansion, and adipocyte hypertrophy in high‐fat diet‐fed mice, while improving serum and hepatic lipid profiles. Mechanistically, the tea promoted fatty acid oxidation via the AMPK–ACC–CPT‐1 axis, while inhibiting lipogenesis by downregulating FAS and reducing inflammatory markers such as TNF‐α and iNOS. Among different storage years, the 2006 vintage showed the strongest antiobesity effects, outperforming teas from 2016 and 1996. Fang et al. (2023) further systematically compared the antiobesity mechanisms of Wuyi rock teas (vintages 2001, 2011, and 2020) in mice. All three tea extracts significantly alleviated diet‐induced obesity and liver injury, albeit through distinct pathways: older vintages primarily modulated lipid metabolism via the AMPK/SREBP‐1 pathway, whereas younger ones relied more on gut microbiota remodeling, particularly enriching Akkermansia. The 2011 vintage demonstrated optimal overall efficacy, likely attributable to synergistic interactions among constituents such as GA and alkaloids. Furthermore, even relatively short‐term storage influences the bioactivity of Oolong tea. A study revealed that the antibacterial capacity of Oolong tea was enhanced with increasing storage duration over periods of 2, 4, 8, 12, and 16 weeks (Cui et al. 2024).

Aged RiPT shows superior bioactivity to nonaged tea in murine models (Figure 4B). Hu et al. (2021) compared 14‐year‐aged (2006) and nonaged (2020) RiPT in DSS‐induced colitis mice. The aged tea alleviated intestinal immune barrier dysfunction through multiple mechanisms: remodeling gut microbiota (e.g., increasing beneficial bacteria), suppressing the TLR4/MyD88/ROS/p38MAPK/NF‐κB p65 pathway, enhancing tight junction protein expression, and promoting macrophage M2 polarization. These effects correlated with elevated tea polysaccharides level after aging. Aged Liupao tea similarly exhibits enhanced efficacy. According to Hu et al. (2021), 7‐year‐aged Liupao tea showed stronger inhibition of α‐glucosidase and advanced glycation end products than the 5‐year‐aged version. Both teas improved glucose consumption in insulin‐resistant LO2 hepatocytes, reduced inflammatory cytokines, elevated superoxide dismutase and insulin‐like growth factor levels, and modulated key metabolic enzymes (PEPCK, G‐6‐Pase, GS), with the 7‐year‐aged sample being more effective. Compositional analysis suggested the enhanced bioactivity may relate to higher TFs, TRs, and TBs content.

Overall, across RaPT, white, and HBOT, the aging process drives a structural shift in health‐promoting constituents from monomeric phenols to polymerized compounds (e.g., EPSFs and TBs), leading to a distinct reprogramming of bioactivity. These teas exhibit a consistent age‐dependent mechanistic migration: fresh teas primarily rely on unoxidized catechins for direct efficacy, whereas aged teas shift toward relying on transformation products to systemically regulate gut microbiota, host metabolism, and cell signaling pathways. However, this evolution of efficacy is not infinite; it displays significant nonlinearity. Notably, studies on Oolong tea reveal an optimal aging window, where moderate aging (approximately 10 years) achieves a synergistic balance between retained active precursors and generated transformation products, yielding superior overall efficacy compared to fresh or excessively aged (e.g., 30 years) samples. Thus, while aging generally endows tea with new functional value, the ultimate health benefits depend on the specific composition and synergy of key active substances at a given vintage. While current studies provide compelling mechanistic insights into the health benefits of aged teas and the chemical shift from monomers to polymers (e.g., EPSFs and TBs), a clear evidence hierarchy must be maintained when interpreting these results. The majority of current evidence relies heavily on in vitro enzyme inhibition assays and in vivo murine models. However, it must be noted that these outcomes are highly dependent on the specific animal models, extraction protocols, and tea matrix confounders used in these studies. Translating these preclinical findings to human health requires extreme caution due to inherent translational uncertainties and issues of dose realism. Therefore, overgeneralizing murine data to predict human health outcomes should be avoided until rigorous human observational and clinical intervention trials validate these “optimal aging windows” under realistic consumption patterns. Ultimately, a universal optimum should be definitively established through comprehensive meta‐analyses.

4. Dating the Age: Authentication Technologies for Aged Tea

The high market value of aged tea often leads to age falsification, necessitating accurate dating for quality assurance. Moving beyond subjective sensory assessment, modern approaches integrate instrumental analysis with chemometrics to establish relatively objective chemical markers for determining storage years. The composition and concentration of these markers, including both volatile and nonvolatile compounds, serve as quantitative indicators for precise age determination. For nonvolatile profiling, near‐infrared spectroscopy has proven to be an intelligent and rapid tool for evaluating key taste constituents, such as the polyphenols‐to‐amino acids ratio, directly from tea matrices (Guo et al. 2021). For characteristic compounds with proven significant vintage differences, such as EPSFs, constructing a linear regression model is sufficient to achieve precise prediction with an error of less than 2 years (R ² train = 0.9294, R ² test = 0.8812; Xie et al. 2019). Regarding the capture of volatile features, high‐throughput technologies like PTR‐TOF‐MS have demonstrated significant advantages. By combining principal component analysis (PCA) for dimensionality reduction and visualization with supervised algorithms such as linear discriminant analysis (LDA), rapid classification of teas from different vintages has been effectively achieved with over 96% accuracy (Wu et al. 2022). With the widespread application of sensors such as electronic tongues, electronic eyes, and spectroscopy, the high‐dimensional data they generate pose challenges to traditional chemometrics, driving a paradigm shift in data processing toward artificial intelligence. In particular, the integration of visual and near‐infrared spectroscopy (Vis/NIRS) and imaging techniques with AI has shown tremendous potential for the nondestructive quality evaluation and dynamic monitoring of tea processing (Li et al. 2025). Addressing small‐sample, high‐dimensional sensor signals, convolutional neural networks (CNNs) have exhibited feature extraction capabilities surpassing traditional models. In particular, the introduction of transfer learning algorithms has effectively resolved the overfitting issue caused by insufficient sample sizes in tea vintage research, significantly improving prediction accuracy (Yang, Miao, et al. 2021). Further research indicates that single‐modal sensing has blind spots, whereas a multimodal fusion strategy using dual‐channel CNNs to synergistically process visual and gustatory signals can construct digital models with higher accuracy, exceeding 98% in both accuracy and precision (Yang, Gao, et al. 2021). Alongside algorithmic optimization, the intervention of advanced materials science has empowered vintage prediction. On one hand, nanomaterials are used to enhance spectral signal response. For example, sensors modified with porphyrin‐functionalized graphene oxide (GO‐TAP) can significantly amplify characteristic peaks in mid‐infrared spectra, achieving 100% accuracy in distinguishing Pu‐erh tea aging vintages when combined with chemometric algorithms (Wei et al. 2020). On the other hand, colorimetric sensor arrays provide a low‐cost solution for rapid on‐site detection (Jiang et al. 2020). Utilizing specific chromogenic reactions between their enzyme‐like activity and tea polyphenols, visual colorimetric fingerprints can be generated, enabling rapid discrimination of White Peony tea vintages without large‐scale precision instruments (Jin et al. 2025). This cost‐effective methodology extends beyond white tea; for instance, composite nanocolorimetric sensor arrays have been successfully utilized for the olfactory analysis and sensory quality assessment of Oolong tea (Lin, Dai, et al. 2024). Similarly, comprehensive noninvasive models integrating appearance, taste, and aroma characteristics have recently been developed to provide a robust “three‐in‐one” anticipation of white tea vintages (Tian et al. 2025).

However, some existing models are constructed based on specific, singular storage environments and raw materials, resulting in insufficient generalization ability when facing samples from different storage conditions and raw material sources. Current analytical modalities for tea vintage authentication possess distinct advantages and limitations regarding their generalization capabilities and deployment readiness (Table S4). Industry 5.0 offers potential directions for addressing these issues, which are discussed in detail in Section 6.

5. Accelerated Aging Technologies

Under appropriate conditions, the aging of dark tea, white tea, and HBOT can significantly enhance their flavor profiles. However, traditional natural aging is an extremely slow process and demands substantial storage resources. As a result, rapid aging technologies have been developed and are promising but preliminary. These techniques generally involve modulating storage conditions (e.g., temperature and humidity) or inoculating specific microorganisms to accelerate the aging process, achieving a tea quality comparable to that of naturally aged tea in a considerably shorter time. According to Qi et al. (2018), white tea rapidly aged under 45–50°C for 180 days exhibited a notable sweet and herbal scent profile, closely resembling that of a 12‐year naturally aged white tea, unlike the control tea aged at room temperature.

Beyond environmental modulation, microbial inoculation has also shown potential for accelerating tea aging. Zhu et al. (2024) inoculated E. cristatum into Shoumei white tea, observing that a brief “flowering process” of just 7 days imparted aged, date‐like, and sweet aromas, typical characteristics of well‐aged white tea. This suggests that E. cristatum‐mediated fermentation offers a promising rapid‐aging approach.

UV‐C irradiation of loose RaPT was found to enhance aroma complexity, reduce astringency and bitterness, and shift its flavor profile closer to that of naturally aged tea. This effect may relate to UV‐induced enzymatic activity regulation (Zhang, Feng, et al. 2025). Notably, just 8 h of UV‐C exposure induced measurable aging effects, yielding flavor scores comparable to those of naturally aged samples in attributes such as sweet aroma, astringency, mellowness, smoothness, and freshness, thereby offering an efficient and direct acceleration method.

High‐pressure pulsed electric field (HPEF) technology has also been applied to tea aging. Zhang et al. (2020) treated RaPT from 2015 to 2017 with HPEF and analyzed volatile compounds using gas chromatography‐mass spectrometry and an electronic nose combined with multivariate statistics. Under optimal parameters (18 kV, 198.4 Hz, 45 min), seven new aroma compounds were detected, and partial least squares modeling indicated an average reduction of 4 years in equivalent aging time, for example, tea from 2015 reached a quality comparable to that of 2011. In other words, under HPEF treatment, the aroma profile of the tea samples became more similar to that of naturally aged tea. The study concluded that HPEF promotes aging by accelerating sulfur‐containing amino acid transformation and oxidation, providing a rapid physical processing solution for Pu‐erh tea.

Although artificially elevated humidity can facilitate chemical transformations during aging to some extent, it simultaneously poses a risk of microbial contamination. From a microbiological safety perspective, physical acceleration methods offer distinct advantages over traditional warm/humid accelerated storage. High‐humidity environments inherently carry a persistent risk of undesired fungal blooms and subsequent mycotoxin (e.g., aflatoxin) contamination. In contrast, treatments like UV‐C exert a broad‐spectrum sterilization effect, significantly reducing the residual microbiota on the tea leaves. This sterilization fundamentally mitigates mycotoxin risks, offering a safer and highly controlled pathway for industrial rapid aging.

Collectively, these findings illustrate a significant technological evolution in artificial aging, characterized by a transition from passive environmental modulation to active biological and high‐energy physical interventions. A distinct hierarchy in the aging acceleration capability is evident: novel nonthermal technologies (UV‐C and HPEF) shift the sensory profile of young tea toward that of naturally aged tea within hours or minutes—a transformation that typically requires days through microbial fermentation or months via thermal treatment. This suggests that while biological methods are distinctively effective at reconstructing specific microbial‐derived flavor profiles, high‐efficiency physical fields offer the most promising potential for industrial scalability by precisely targeting key chemical mechanisms to bypass the temporal constraints of natural aging.

Current evidence suggests that while accelerated aging methods, such as UV‐C and HPEF, can rapidly drive specific chemical shifts and simulate certain indicators (e.g., aroma or taste profile) of long‐term natural aging, they do not perfectly replicate its holistic complexity. For example, utilizing controlled UV‐C and HPEF have successfully demonstrated sensory profiles closely mimicking 5‐year naturally aged Pu‐erh teas, characterized by enhanced mellowness and aged aroma (Zhang, Feng, et al. 2025). Therefore, sensory blind validation against naturally aged exemplars using quantitative descriptive analysis (QDA) is strictly necessary to prevent the misapplication of these technologies. Consequently, to guide industrial applications and ensure the strict quality control of rapidly aged teas, we propose a concise, multidimensional validation checklist. True equivalence to naturally aged teas should be verified through the following strict criteria: (1) Sensory Equivalence: Blind human sensory evaluation (e.g., QDA) must demonstrate high overall similarity to naturally aged benchmarks. Crucially, there must be a strict absence of photolysis‐induced off‐notes, thermal degradation defects, or earthy/musty odors. (2) Targeted Chemical Markers: Chemical profiling must verify the reduction of grassy volatiles (e.g., hexanal) alongside the de novo accumulation of core aging markers, specifically EPSFs, TBs, and aged‐specific terpenes. (3) Microbiological and Toxin Safety: For any accelerated aging method involving humidity control, rigorous microbiological and toxicological testing must be mandatory post‐treatment to ensure strict compliance with relevant food safety standards. Targeted screening must verify the complete absence of pathogenic contamination and mycotoxins (e.g., aflatoxin B1).

Regarding safety and quality, the parameters of physical interventions must be finely tuned to avoid photolysis‐induced off‐notes. Controlled UV‐C effectively degrades chlorophyll and reduces grassy volatiles (e.g., hexanal) while promoting the accumulation of desirable floral/woody terpenes like ionones and linalool oxides without detrimental photolytic degradation. Furthermore, to completely avoid potential chemical migration or UV‐induced packaging interactions, these treatments must be applied strictly to loose tea leaves prior to final packaging.

6. Forward‐Looking Blueprint: Implementation of Industry 5.0 in the Aged Tea Sector

The aged tea industry encompasses multiple stages, including processing, storage, and distribution, with product quality heavily reliant on chemical transformations and environmental control during the aging process. With the emergence of Industry 4.0 and Industry 5.0 technologies, innovative tools such as Digital Twins, the IoT, and blockchain are gradually being integrated into this traditional sector to enhance efficiency, ensure quality consistency, and promote sustainable development (Figure 5; Hassoun et al. 2024). Industry 4.0 focuses on automation and data‐driven optimization, while Industry 5.0 emphasizes human‐machine collaboration and ecological friendliness; together, they provide a comprehensive technological framework for the aged tea industry. This section systematically elaborates on the applications, practical examples, and challenges associated with these technologies.

FIGURE 5.

Integration framework of cutting‐edge technologies such as Digital Twin, Internet of Things (IoT), and blockchain in the aged tea industry. (A) IoT can be used to collect various environmental data throughout the processes of planting, processing, aging, and circulation of aged tea, enabling full‐process management of aged tea production. Particularly during the critical storage and aging stage, IoT sensors monitor environmental parameters such as temperature, humidity, and O₂ in real‐time. The data are uploaded to the cloud platform via gateways, achieving full‐chain environmental visibility. (B) Based on key process and quality data collected by IoT, blockchain technology is employed to encrypt and record information on the chain, creating an immutable traceability record. This ensures end‐to‐end traceability and anticounterfeiting verification from the tea garden to the consumer, with a particular focus on the aging year. (C) A digital twin model of the tea aging process is constructed using multisource data. Machine learning algorithms simulate flavor evolution and predict quality trends, outputting aging strategies. The system dynamically adjusts the physical environment through IoT actuators (such as dehumidifiers and temperature control devices), forming a closed‐loop control of “monitoring–simulation–decision–execution.” This enables precise management and personalized customization of the aging process.

Digital twin technology constructs high‐fidelity dynamic virtual models of physical entities by integrating sensors, data analytics, and simulation techniques (Hassoun et al. 2023), enabling real‐time monitoring and predictive analysis of physical processes. In the context of tea aging, this technology can simulate complex maturation processes through computational models to accurately predict flavor evolution and biochemical transformations. The system integrates multisource data, including sensory profiles, quantitative flavor compound data, and historical aging databases of various tea varieties. Using machine learning algorithms, it models the impact of environmental conditions on chemical reactions, predicting aging pathways and optimal timeframes required for specific flavor profiles. The broader application of computer vision and machine learning within the tea industry is rapidly advancing, providing the essential algorithmic frameworks needed to empower these digital twin systems (Wang, Gu, et al. 2023). This helps producers avoid quality degradation due to overaging while improving product consistency. By integrating consumer preference data, it further supports decision‐making for customized aging protocols. However, high‐precision digital twins still face challenges such as data heterogeneity, high computational costs, and limited model interpretability.

The integration of IoT and sensor technologies addresses the critical need for precise monitoring and dynamic control within tea aging storage systems (Liu, Yu, et al. 2025). A comprehensive multimodal sensor network (e.g., temperature, humidity, oxygen, CO₂, and light sensors) continuously collects environmental parameters. In parallel, specialized gas sensor detection systems have been implemented to monitor dynamic changes in volatile organic compounds (VOCs) in real‐time, offering direct insights into aroma evolution during storage and processing (Han et al. 2024). Data transmission occurs through IoT gateways to cloud platforms or edge nodes, where AI algorithms perform real‐time analysis and predict chemical transformation trends. Building upon digital twin feedback, the system autonomously triggers actuators to fine‐tune environmental conditions. Alternatively, technical professionals can adjust aging parameters based on market requirements, ultimately achieving precise control over the tea aging process. Furthermore, solution‐phase sensor arrays combined with UV–visible spectroscopy have proven to be highly effective for the rapid, real‐time monitoring of fermentation quality, ensuring consistent biochemical progression (Li, Li, et al. 2022). For instance, when humidity sensors detect elevated levels, the system initiates dehumidification protocols to prevent mold formation, while oxygen concentration adjustments help regulate aging rates and reduce energy consumption.

Blockchain technology serves as a distributed ledger system that significantly enhances traceability and anticounterfeiting measures for aged tea products (Liu, Yu, et al. 2025). By cryptographically recording key information, including raw material origins, storage duration, environmental logs (e.g., temperature and humidity history), and certification details, on an immutable chain, blockchain ensures full supply chain transparency from cultivation to consumer. Practical implementations include embedding RFID tags in tea products, allowing consumers to access blockchain records via QR code scanning to verify production dates, aging conditions, and other critical information, thereby effectively combating label fraud.

To transition from theoretical frameworks to realistic implementation, we propose a worked example of a 5–10 ton digital twin pilot warehouse for tea aging. Setting up this facility requires a high‐density deployment of industrial‐grade sensors, including multipoint temperature and RH probes, O₂/CO₂ concentration monitors, and airflow velocity sensors. The digital twin utilizes edge‐computing to maintain dynamic control logic; for example, to facilitate steady nonenzymatic oxidation while preventing fungal proliferation, the system maintains a baseline temperature of 22–25°C and an RH setpoint of 55%–60%, while automatically triggering fresh air intake if O₂ levels drop below 18%. In this setup, while automated heating, ventilation, and air conditioning (HVAC) systems handle minute‐by‐minute microadjustments, human intervention cadence is significantly reduced to monthly sensory quality checks and biannual physical sensor recalibration. Economically, establishing such a pilot facility requires an estimated Capital Expenditure of $15,000–$25,000, which encompasses industrial IoT sensors, edge gateways, automated HVAC retrofitting, and basic software licensing. The Operational Expenditure, covering cloud storage, software maintenance, and sensor calibration, is estimated at $3000–$5000 annually, offering a realistic entry point for medium‐scale tea enterprises.

Successful digital integration also requires strict adherence to minimum viable data standards to prevent fragmented data silos. Telemetry data from tea warehouses should utilize lightweight IoT protocols like message queuing telemetry transport, transmitting data in standardized JavaScript object notation formats to ensure interoperability across different analytical platforms. Additionally, mandatory calibration routines must be codified, requiring hardware calibration every 6 months using saturated salt solutions for RH sensors to combat baseline drift. Furthermore, an industry‐wide ontology for tea states must be established, utilizing standardized metadata tags (e.g., State: Raw_Withering, State: Dry_Aged_Phase1) to allow machine learning algorithms to accurately cross‐reference aging models across different geographical facilities. Despite these technological advantages, the deployment of Industry 5.0 architectures introduces novel vulnerabilities. To practically guide industry readers, Table S5 outlines a comprehensive risk register and corresponding mitigation strategies for IoT‐enabled tea facilities.

Despite these promising technological advancements, widespread implementation in the traditional tea sector, particularly among small and medium‐sized enterprises, faces substantial practical hurdles. The primary barrier is the significant financial burden associated with the high initial investment and ongoing operational costs required for deploying high‐precision sensor networks, blockchain infrastructure, and digital twin systems, which often exceed the limited margins of traditional producers. Furthermore, the industry grapples with a critical shortage of interdisciplinary talent capable of bridging the gap between traditional tea craftsmanship and modern digital technologies, such as data analytics, IoT maintenance, and algorithm optimization. This challenge is further compounded by the lack of data standardization and system compatibility, which frequently results in data silos that complicate the integration of information across the entire value chain. Consequently, developing cost‐effective, modular solutions and establishing universal industry data standards are essential prerequisites for the broader adoption of Industry 5.0 in the aged tea sector.

7. Challenges and Future Perspectives

Aged tea has garnered significant attention due to its unique sensory properties, potential health benefits, and commercial value. However, scientific research and industrial development in this field continue to face critical challenges.

At the fundamental research level, the flavor evolution of aged tea and its underlying mechanisms have not been systematically elucidated. On one hand, most existing studies rely on commercially available samples, which often consist of raw materials from different years, batches, regions, seasons, and quality grades, frequently blended before sale. This inherent heterogeneity in sample composition makes it difficult to attribute chemical changes solely to aging duration, leading to considerable inconsistencies across studies. On the other hand, current insights into the transformation mechanisms of chemical constituents are predominantly derived from correlational analyses rather than causal verification. Therefore, beyond ensuring the homogeneity of raw materials, future research should incorporate advanced molecular methodologies. For instance, employing stable isotope probing to trace substrate transformation pathways, or constructing synthetic microbial communities, would allow for the definitive identification of functional strains and enzymes responsible for key flavor formation, thereby unraveling the core biochemical mechanisms of tea aging. Furthermore, decoding the precise olfactory impact of aged tea requires a shift toward molecular sensory science. Since olfactory signal transduction is governed by G protein‐coupled receptors detecting specific odorants (Guo et al. 2026), future investigations should prioritize screening key aged‐aroma compounds (e.g., specific methoxybenzenes and terpenes) against human olfactory GPCRs. Identifying the specific receptors targeted by these volatiles will provide a definitive biological basis for how the characteristic aged aroma is physiologically perceived. On the sensory evaluation front, there is a critical need to transition from subjective descriptive profiling to objective neurocognitive methodologies. For example, applying electroencephalography to aged tea research will be instrumental in decoding the exact neural mechanisms underlying its complex perceptual traits, particularly its signature mellow and thick attributes (He et al. 2025).

From an industrial standardization perspective, the absence of a scientifically grounded quality evaluation system and uniform storage standards has resulted in market irregularities (e.g., misrepresentation of quality and falsification of aging claims) which undermine consumer trust and industry credibility. There is an urgent need to establish category‐specific standards that integrate chemical composition, storage conditions, and sensory quality, supported by high‐sensitivity marker detection and AI‐driven traceability methods. Blockchain‐based traceability systems for tea aging vintages are also expected to curb vintage falsification.

At the technological application level, natural aging is notoriously slow and susceptible to environmental fluctuations, while current artificial acceleration techniques often fail to replicate the complex flavor profiles of naturally aged tea. Future efforts must identify key flavor determinants and elucidate the regulatory mechanisms of environmental factors on chemical transformations. Building upon this foundation, adopting Industry 5.0 paradigms such as Digital Twins and AI‐driven dynamic control will facilitate the establishment of green and intelligent aging technologies to achieve the accelerated yet precise transformation of tea quality.

In summary, breakthroughs in mechanistic understanding, standard establishment, and technological innovation are essential to transition the aged tea industry from experience‐based practice to a scientifically guided, standardized, and high‐quality development path. Finally, it should be emphasized that longer aging does not always mean better quality; consumers are encouraged to make informed choices based on personal preference and rational needs.

8. Conclusion

Although the initial chemical composition varies considerably among tea types due to distinct manufacturing processes, their chemical transformations during aging follow shared fundamental pathways dictated by their prestorage processing. For teas with milder initial processing (e.g., RaPT and white tea), the hydrolysis and oxidative polymerization of catechins represent the central route driving flavor evolution. This pathway not only leads to a reduction in astringency and bitterness but also progressively yields polymeric pigments including TFs, TRs, and TBs, which collectively establish the characteristic mellow and thick taste and deep reddish hue of well‐aged teas. Concurrently, the formation of EPSFs, generated from reactions between theanine and catechins, serves as a chemical marker of aging. Conversely, for teas undergoing intense initial processing (e.g., RiPT and HBOT), postprocessing aging is predominantly driven by volatile evolution, as their nonvolatile phenolics have largely stabilized during early manufacturing. The distinctive aged aroma, a complex scent profile encompassing notes (e.g., stale, woody, and herbal), constitutes a critical sensory attribute of aged tea. Crucially, storage parameters, including temperature, humidity, and oxygen availability, act as key drivers that govern the pace and direction of aging by modulating reaction rates and pathways. While elevated temperature and humidity can markedly accelerate chemical conversion, they often do so at the expense of flavor complexity and product safety. In contrast, a stable and controlled dry storage environment favors the harmonious and gradual development of flavors toward high‐quality maturation.

Regarding health attributes, aging entails more than a simple decline in classic bioactive compounds. Although levels of certain polyphenols and amino acids decrease during storage, specific compounds that accumulate over time (EPSFs and TBs) have demonstrated various bioactivities, including anti‐inflammatory effects, regulation of glucose and lipid metabolism, and modulation of gut health. This evidence indicates a distinct paradigm shift in the health value composition of aged tea: from a direct therapeutic reliance on unoxidized monomeric active compounds predominant in fresh leaves to a systemic mode of action driven by polymers and novel constituents formed during the aging process. Furthermore, this efficacy evolution is significantly nonlinear, peaking at an optimal maturation stage rather than extending infinitely.

The future of the aged tea industry lies in transitioning from reliance on traditional empirical knowledge to a foundation built on scientific principles, standardization, and intelligent technology. To achieve this, we actively challenge the persistent industry myth that “older is always better”; rather, aging is a complex process with an “optimal aging window” that balances sensory maturation and health benefits. Identifying this window provides practitioners with a concrete decision‐making paradigm to prevent quality deterioration and optimize inventory turnover. Moreover, we deliver an actionable blueprint for the sector's modernization by integrating Industry 5.0 technologies, such as Digital Twins, IoT, and Blockchain. This framework enables the transition from uncontrolled natural aging to precise environmental control, targeted accelerated aging, and robust vintage authentication. Consumers are encouraged to make informed choices based on personal preference and scientific understanding. Substantial progress in mechanistic exploration, standard establishment, and technological innovation is essential to steer this ancient and distinctive beverage toward a future of high‐quality and sustainable development.

Author Contributions

Yan Liu: writing – original draft, conceptualization, investigation, visualization. Rongbosen Yue: visualization. Yucheng Zou: visualization. Sibo Zhao: investigation. Jielin Jiang: writing – original draft. Liyong Luo: project administration. Zhonghua Liu: writing – review and editing, supervision. Liang Zeng: writing – review and editing, funding acquisition, project administration, supervision.

Conflicts of Interest

Jielin Jiang is studying for a doctorate at Southwest University's College of Food Science while working for Yunnan TAETEA Group Co., Ltd., a company that produces and sells Pu‐erh tea. The authors confirm that Jiang's employment did not affect the review's conclusions. The company played no part in planning the research, analyzing data, writing the paper, or deciding to publish these results. The other authors declare no conflicts of interest.

Supporting information

TABLE S1 crf370589‐sup‐0001‐TableS1.docx

TABLE S2 crf370589‐sup‐0002‐TableS2.docx

TABLE S3 crf370589‐sup‐0003‐TableS3.docx

TABLE S4 crf370589‐sup‐0004‐TableS4.docx

TABLE S5 crf370589‐sup‐0005‐TableS5.docx

Data Availability Statement

No data were used for the research described in this review.