After three to four years, when they reach maturity, coffee trees bear fruit in lines or clusters along the branches of the trees. Referred to as a berry or cherry, this fruit turns red when it is ready to be harvested. Coffee beans are actually the seeds of these ripened cherries. Most arabica cherries ripen after 6-8 months; robusta beans take between 9 and 11 months to ripen.

Beneath the cherries' red skin (exocar) is a fleshy pulp (mesocarp), a slimy layer (parenchyma), and a parchment-like covering of the bean (endocarp). Inside these layers are usually two beans, which are covered by a thin membrane or coat. This membrane or seed skin (spermoderm), is referred to in the coffee trade as the “silver skin.”

Harvest times vary according to geographical zone, but typically there is only one harvest a year. North of the Equator, the harvest takes place between September and March. South of the Equator, the main harvest occurs in April or May, although it may last until August. In countries in which the division between wet and dry seasons is not clearly defined -- like Colombia and Kenya -- there may be two flowerings a year, therefore permitting a main and a secondary crop. Equatorial countries can harvest fruit all year round.

The vast majority of coffee is harvested by hand in one of two ways: 1) strip picking or 2) selective picking. Strip picking means the entire crop is picked in one pass. Selective picking involves making several passes among the coffee trees at intervals of eight to 10 days so that only the fully ripe berries are taken. Selective picking is more expensive and, when used, is used only for arabica beans.

On an average farm, pickers gather between 100 and 200 pounds of cherries per day. Of this total weight, 20 percent is actually bean (20 to 40 pounds). Coffee beans from the farm are bundled and shipped in 100 to 130 pound bags. Therefore it takes one picker three to six days to fill one bag.