The coffee plant prefers the cool, moist, frost-free climate found at higher altitudes in the tropics and subtropics. Optimum growing conditions include: temperature of about 75 degrees Fahrenheit (24 degrees Celsius); well-distributed annual rainfall of about 50 in. (127 cm) with a short dry season; and fertile, deep, well-drained soil, especially of volcanic origin. While coffee can be grown from sea level to c.6,000 ft (1,830 m), and C. robusta is produced at low elevations in West Africa, the better arabica grades are generally produced above 1,500 ft (460 m). Strong winds limit coffee production; coffee is often grown in the shelter of taller trees. A coffee tree yields its maximum sometime between its fifth and tenth year and may bear for about 30 years.

After the outer pulp is removed, coffee seeds are prepared by roasting, which develops the aroma and flavor of their essential oils. Longer roasting produces darker, stronger coffee. The variety of recipes and prescriptions for roasting, brewing, and serving coffee reflects the diversity of consumer tastes and cultural preferences. All techniques begin with properly roasted, freshly ground coffee; freshly boiling water; and absolutely clean utensils. Turkish coffee, a strong, unfiltered brew of finely powdered coffee and sugar, is popular in Greece, Turkey, and Arabia. Italian-style espresso, or expresso, is brewed by forcing hot water under pressure through finely powdered, often darkly roasted coffee. Most other coffees are filtered. Café au lait, coffee mixed with scalded milk, is a traditional French breakfast drink, as is café con leche in countries where Spanish is spoken. Coffee flavored with chicory is a specialty of New Orleans. Connoisseurs pay dearly for Mocha from the Yemen region of Arabia, Blue Mountain from Jamaica, Kona from Hawaii, or other so-called specialty coffees from Africa, Indonesia, or Latin America—all premium arabica varieties.

Varieties of C. arabica are important export crops in many countries, especially in South America and East Africa. Brazil is the leading producer. The only other species of commercial importance is C. robusta, a West African native also widely grown in Central Africa and Asia. Fluctuations in supply and demand have historically played havoc with world coffee markets and with the economies of individual growers and exporting countries. Efforts to stabilize the markets began with a 1940 agreement, administered by the Inter-American Coffee Board, allocating U.S. coffee imports from Latin America. A global agreement under the International Coffee Organization, a body of 70 coffee-producing and -consuming countries, expired in 1989.

In many cultures throughout its history, coffee has been served in coffeehouses, cafés, and other places of public refreshment, often as an aid and accompaniment to political or artistic activity, gambling, or gossip, or to solo rumination. Coffee's popularity in the United States peaked in 1962, when three-quarters of people over 10 years of age drank at least a cup a day; in 1992 only about half did. Beginning about 1990 U.S. consumers became increasingly interested in premium coffees and stronger, richer brews.

Coffee is classified in the division Magnoliophyta, class Magnoliopsida, order Rubiales, family Rubiaceae (madder).

See G. Dicum and N. Luttinger, The Coffee Book (1999); M. Pendergrast, Uncommon Grounds (1999).