Coffee is a brewed drink prepared from roasted coffee beans, which are the seeds of berries from the Coffea plant. The Coffea plant is native to subtropical Africa and some islands in southern Asia.[2] The plant was exported from Africa to countries around the world and coffee plants are now cultivated in over 70 countries, primarily in the equatorial regions of the Americas, Southeast Asia, India, and Africa. The two most commonly grown are the highly regarded arabica, and the less sophisticated but stronger and more hardy robusta. Once ripe, coffee beans are picked, processed, and dried. Dried coffee beans are roasted to varying degrees, depending on the desired flavor. Roasted beans are ground and brewed to produce coffee as a beverage.
Coffee is slightly acidic and can have a stimulating effect on humans because of its caffeine content. Coffee is one of the most popular drinks in the world.[3] It can be prepared and presented in a variety of ways (e.g., espresso, cappuccino, cafe latte, etc.). It is usually served hot, although iced coffee is also served. The majority of recent research suggests that moderate coffee consumption is benign or mildly beneficial in healthy adults.[citation needed]
The earliest credible evidence of coffee-drinking appears in the middle of the 15th century in the Sufi shrines of Yemen.[4] It was here in Arabia that coffee seeds were first roasted and brewed, in a similar way to how it is now prepared. Coffee seeds were first exported from Ethiopia to Yemen, as the coffee plant is thought to have been indigenous to the former.[5] Yemeni traders took coffee back to their homeland and began to cultivate the seed. By the 16th century, it had reached the rest of the Middle East, Persia, Turkey, and northern Africa. From there, it spread to Europe and the rest of the world.
Coffee is a major export commodity: it is the top agricultural export for numerous countries and among the world's largest legal agricultural export.[3][6] and one of the most valuable commodities exported by developing countries. Green (unroasted) coffee is one of the most traded agricultural commodities in the world.[7] Some controversy is associated with coffee cultivation and the way developed countries trade with developing nations and the impact of its cultivation on the environment, in regards to clearing of land for coffee-growing and water use. Consequently, fair trade coffee and organic coffee are an expanding market.