Coffee is the world's most common source of caffeine, a stimulant. In the United States, coffee is usually made by percolation or infusion from the roasted and ground or pounded seeds of the coffee tree (genus Coffea). This tree was native to Africa but now is grown widely in warm regions for commercial crops. More than half of adolescents and adults in the United States drink some type of coffee beverage.

See Also

Caffeine; Cola Drinks; Tea.