A coffee bean (Arabic بُن bunn) is a seed of the coffee plant, and is the source for coffee. It is the pit inside the red or purple fruit often referred to as a cherry. Even though they are seeds, they are incorrectly referred to as 'beans' because of their resemblance to true beans. The fruits - coffee cherries or coffee berries - most contain two stones with their flat sides together. A minimum percentage of cherries contain a single seed, instead of the usual two. This is called a peaberry. Like Brazil nuts (a seed) and white rice, coffee seeds consist mostly of endosperm.
The two most economically important varieties of coffee plant are the Arabica and the Robusta; 75-80% of the coffee produced worldwide is Arabica and 20% is Robusta. Arabica seeds consist of 0.8-1.4% caffeine and Robusta seeds consist of 1.7-4% caffeine. As coffee is one of the world's most widely consumed beverages, coffee seeds are a major cash crop, and an important export product, counting for over 50% of some developing nations' foreign exchange earnings. The United States imports more coffee than any other nation. In 2009 the average person in the United States consumed 4.09 kg (9 lbs) of coffee.
Coffee is a brewed beverage with a distinct aroma and flavor, prepared from the roasted seeds of the Coffea plant. The seeds are found in coffee "berries", which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia, Maldives, and Africa. Green (unroasted) coffee is one of the most traded agricultural commodities in the world. Coffee is slightly acidic (pH 5.0–5.1) and can have a stimulating effect on humans because of its caffeine content. It is one of the most consumed drinks in the world.
Wild coffee's energizing effect was likely first discovered in the northeast region of Ethiopia. Coffee cultivation first took place in southern Arabia; the earliest credible evidence of coffee-drinking appears in the middle of the 15th century in the Sufi shrines of Yemen.
In East Africa and Yemen, coffee was used in native religious ceremonies that were in competition with the Christian Church. As a result, the Ethiopian Church banned its secular consumption until the reign of Emperor Menelik II of Ethiopia. The beverage was also banned in Ottoman Turkey during the 17th century for political reasons and was associated with rebellious political activities in Europe.