A coffee bean is a seed of the Coffea plant and the source for coffee. It is the pit inside the red or purple fruit often referred to as a cherry. Just like ordinary cherries, the coffee fruit is also a so-called stone fruit. Even though the coffee beans are not technically beans, they are referred to as such because of their resemblance to true beans. The fruits – coffee cherries or coffee berries – most commonly contain two stones with their flat sides together. A small percentage of cherries contain a single seed, instead of the usual two. This is called a "peaberry". The peaberry occurs only between 10 and 15% of the time, and it is a fairly common (yet scientifically unproven) belief that they have more flavour than normal coffee beans. Like Brazil nuts (a seed) and white rice, coffee beans consist mostly of endosperm.
The two most economically important varieties of coffee plant are the Arabica and the Robusta; ~60% of the coffee produced worldwide is Arabica and ~40% is Robusta. Arabica beans consist of 0.8–1.4% caffeine and Robusta beans consist of 1.7–4% caffeine. As coffee is one of the world's most widely consumed beverages, coffee beans are a major cash crop and an important export product, accounting for over 50% of some developing nations' foreign exchange earnings.
Coffee is the drink obtained from the roasted and ground beans of
the coffee plant (caffeine); it is highly stimulating because of its caffeine content, a psychoactive substance. This product is one of the most commercialized in the world and one of the three most consumed beverages in the world (along with water and tea). It is usually taken at breakfast, after breakfast or even as the only breakfast, although it is also often taken at snack time, or after lunch or dinner for conversation or
just out of habit. It is one of the most socializing soft drinks in many countries.
The taste for coffee is not spontaneous, but must be cultivated, since its flavor is strong
and bitter.
The coffee tree averages from 5–10 m (16–33 ft) in height. As the tree gets older, it branches less and less and bears more leaves and fruits.
Coffee plants are grown in rows several feet apart. Some farmers plant fruit trees around them or plant the coffee on the sides of hills, because they need specific conditions to flourish. Ideally, Arabica coffee beans are grown at temperatures between 15 and 24 °C (59 and 75 °F) and Robusta at 24–30 °C (75–86 °F) and receive between 150 and 300 cm (59 and 118 in) of rainfall per year. Heavy rain is needed in the beginning of the season when the fruit is developing and less later in the season as it ripens.
When the fruit is ripe, it is almost always handpicked, using either "selective picking", where only the ripe fruit is removed, or "strip-picking", where all of the fruit is removed from a limb all at once. This selective picking gives the growers reason to give their coffee a certain specification called "operation cherry red" (OCR).
Two methods are primarily used to process coffee berries. The first, "wet" or "washed" process, has historically usually been carried out in Central America and areas of Africa. The flesh of the cherries is separated from the seeds and then the seeds are fermented – soaked in water for about two days. This softens the mucilage, which is a sticky pulp residue that is still attached to the seeds. Then this mucilage is washed off with water.
The "dry processing" method, cheaper and simpler, was historically used for lower-quality beans in Brazil and much of Africa, but now brings a premium when done well. Twigs and other foreign objects are separated from the berries and the fruit is then spread out in the sun on concrete, bricks or raised beds for 2–3 weeks, turned regularly for even drying.