Table 1. Details on the four coffees (Coffea arabica) that were ground in this experiment: two African and two South American.

Farm/Estate	Origin	Variety	Roaster	Roast	Agtron colour
Las Ilusiones (W)	Guatemala	Caturra and Bourbon	Round Hill	Espresso	62
Santa Petrona (W)	El Salvador	Pacamara	Has Bean	Espresso	59
Burka (W)	Tanzania	Red Bourbon	Has Bean	Espresso	59
Sasaba (N)	Ethiopia	Mixed Heirloom	James Gourmet	Filter	68

(W) and (N) indicate washed and natural processing methods, respectively. ‘Roast’ is used as an indication for whether the coffee was roasted for filter (lighter) or espresso (darker) style coffee, and can be quantified by the ‘Agtron colour’ as determined by the Agtron spectrophotometeric measurement⁴⁶. All coffees examined here would be considered light/medium roasted relative to typical commodity grade coffee.