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.
