The fruit of the coffee plant, the drupe, has a cherry-like appearance. As it matures it changes from green to a bright red or yellow. The skin of the drupe is shiny and thick while its pulp is tender and sugary. Inside the drupe, the seeds (future coffee beans) are covered with mucilage, a slimy, sugary layer, and two membranes, one thicker than the other: the silver skin and the parchment.
The fruit harvesting phase is a crucial moment on which the final quality of our coffee depends. The ripening of the fruits has different rhythms, determined by the rains. Thus, in the same plant, we can find unripe, ripe and overripe fruits. For this reason, harvesting is a very delicate process.
Once the harvesting phase is complete, we proceed with the processing that will eliminate the pulp and mucilage of the drupe so as to obtain green coffee. There are two processing categories, and both must begin on the same day of the harvesting.
The most traditional method is the manual one, also called picking, in which only the ripe drupes are selected by hand.
Stripping is the method by which all the fruits present on a single branch are shucked.
It is possible to harvest the drupes mechanically, using shaking machines operating only on flat land such as in the Cerrado Mineiro in Brazil.
In the dry process, the drupes are dried naturally in the sun or mechanically, and then, once dry, the beans are released by dehulling machines, thus producing natural coffee.
In the wet process, the beans are immersed in tanks full of water where the mucilage decomposes, thus releasing the bean. In this case we get washed coffee.
The hulling process is the final stage in which the outer coating is removed from the dried drupe.