Coffee

Coffee comes from evergreen shrubs or small trees in the genus Coffea, in the Rubiaceae family. The part commonly called a coffee bean is a seed inside the plant's fleshy fruit, known as a coffee cherry; most cherries contain two seeds. The two species that supply most commercial coffee are Coffea arabica and Coffea canephora, usually sold as Robusta. They differ in growing conditions and qualities of the brewed drink. Kew's botanical database gives Arabica a native range in eastern South Sudan, southwestern Ethiopia and northern Kenya, while cultivated coffee now grows across tropical regions.

The botanical origins of coffee and the history of the brewed drink are related but not identical questions. Botanical sources identify East Africa as part of Arabica's native range; historical accounts place the cultivation and use of coffee as a hot drink in southern Arabia, especially Yemen, by the fifteenth century. From there it became popular in the wider Islamic world. Coffeehouses appeared in Mecca and later Constantinople, providing settings for conversation and public life. Coffee reached European countries during the sixteenth and seventeenth centuries, and cultivation spread to Java and other parts of the Indonesian archipelago in the seventeenth century and to the Americas in the eighteenth. Stories about a single discoverer, such as the goatherd Kaldi, are legends rather than securely documented origins.

Coffee is grown mainly in tropical parts of the world, but suitable conditions vary by species. Arabica is generally associated with cooler, higher-elevation conditions, whereas Robusta tolerates warmer conditions and can grow at lower elevations. After harvesting, the seeds must be separated from the cherries and dried before roasting. Producers use several processing approaches, including dry (natural), wet (washed) and intermediate methods; these differ in how fruit is removed and the seeds are dried, and can influence the resulting coffee. The dried, unroasted seeds are often called green coffee. Roasting develops much of the familiar aroma, after which the beans may be ground and brewed in many ways.

Coffee's significance extends beyond the drink itself. In Ottoman and Safavid societies, coffeehouses and domestic serving practices became part of urban social life; objects such as pots, cups and trays reflect the craft traditions that grew around serving coffee. Coffeehouses also became meeting places for discussion, although authorities at times restricted them. Preparation and hospitality customs differ across regions, and modern coffee culture includes a wide range of brewing methods and café traditions. At the same time, coffee is a major traded agricultural commodity. The International Coffee Organization maintains information on production, consumption, trade and prices, illustrating how the crop connects growers, exporters, retailers and consumers across countries.