coffee A beverage produced by roasting the beans from the berries of two principal types of shrub: Coffea arabica (arabica coffee) and C. canephora (robusta coffee); Liberian coffee (C. liberica) grows in tropical regions, but quality is inferior and it accounts for less than 1% of world coffee trade. Reputedly discovered in the ninth century in southern Ethiopia by a goatherd whose goats became frisky after eating the berries. Niacin is formed during the roasting process, and coffee can contain 10–40 mg of niacin per 100 g, depending on the extent of roasting, thus making a significant contribution to average intakes of niacin.

Instant coffee (invented by Satori Kato of Chicago, 1901) is dried coffee extract which can be used to make a beverage by adding hot water or milk. It may be manufactured by spray‐drying or freeze‐drying. Coffee essence is an aqueous extract of roasted coffee; usually about 400 g of coffee/L.

Coffee contains caffeine. Decaffeinated coffee is coffee beans (or instant coffee) from which the caffeine has been extracted with solvent (e.g. methylene or ethylene chloride), carbon dioxide under pressure (supercritical CO₂), or water. Coffee decaffeinated by water extraction is sometimes labelled as ‘naturally’ decaffeinated. The first decaffeinated coffee was introduced by German coffee importer Ludwig Roselius, who received a shipment of beans that had been soaked by seawater during a storm, under the trade name of Sanka (from the French sans caffeine), 1903.