Table 1.

Description of coffee samples.

(a) Whole bean samples
		Number of samples	Number of extracts	Comments
Arabica		7	14	Purchased from UK retailers. Includes one decaffeinated sample. Two extracts prepared per sample
				Geographic origins of the beans, as stated on labels: Kenya, Peru (×2), Indonesia, Africa & South America (blend), Africa & Central & South America (blend), 1 × origin not stated
		4	4	Supplied by the British Coffee Association
				Geographic origins of the beans: Colombia, Honduras, Nicaragua, Brazil
Robusta		3	6	Purchased from UK retailers. Two extracts prepared per sample
				Geographic origins of the beans, as stated on labels: India, Tanzania, 1 × origin not stated
		3	3	Supplied by the British Coffee Association
				Geographic origins of the beans: Vietnam, India, Uganda
(b) Mixtures prepared from whole bean samples
% w/w arabica	% w/w robusta	Number of samples	Number of extracts	Comments
90, 80, 70,… 10	10, 20, 30,… 90	18	18	Two mixture series, each prepared from a randomly selected pair of whole bean samples
90, 80, 60	10, 20, 40	36	36	Twelve partial mixture series, each prepared from a different pairwise combination of whole bean samples
(c) Surveillance samples (retail-purchased ground roast coffees)
		Number of samples	Number of extracts	Comments
Labelled “100% arabica”		27	32	Purchased from UK retailers. Includes two decaffeinated samples. Two extracts prepared from five of the samples
				Geographic origins of the beans, as stated on the labels: Indonesia, Central & South America (blend), Africa & Asia & South America (blend), Africa & Brazil & Central America (blend), Guatamala (×3), Latin America, Brazil, Indonesia & Africa & Latin America (blends, ×2), Sumatra, Java, Columbia (×2), Kenya, Java & Sumatra (×2), Costa Rica, “multiple countries of origin” (×3), origin not stated (×5)