CoffeeProcessing Gourmet Coffee Cheeries
What we call a coffee bean is actually the seeds of a cherry-like fruit. Coffee trees produce berries, called coffee cherries, that turn bright red when they are ripe and ready to pick. The fruit is found in clusters along the branches of the tree. The skin of a coffee cherry (the exocarp) is thick and bitter. However, the fruit beneath it (the mesocarp) is intensely sweet and has the texture of a grape. Next comes the parenchyma, a slimy, honey-like layer, which helps protect the beans. The beans themselves are covered by a parchment-like envelope called the endocarp. This protects the two, bluish-green coffee beans, which are covered by yet another membrane, called the spermoderm or silver skin.
There is usually one coffee harvest per year. The time varies according to geographic zone, but generally, north of the Equator, harvest takes place between September and March, and south of the equator between April and May. Coffee is generally harvested by hand, either by stripping all of the cherries off the branch at one time or by selective picking. The latter is more expensive and is only used for arabica beans.
Once picked, the coffee cherries must be processed immediately.Right after picking, it"s time for processing. This is done in one of two ways:
*Dry method - By the simplest and cheapest method, the harvested cherries are spread out to dry in sunlight. They are periodically raked and turned for seven to 10 days, until their moisture content has fallen to 11 percent. The outer shell of the cherries turns brown and the beans rattle around inside.
*Wet method - The main difference between the wet and dry method is that in the wet method, the pulp of the coffee cherry is removed from the beans within 24 hours of harvesting. A pulping machine washes away the skin and pulp. The beans are put in fermentation tanks for 12 to 48 hours. Natural enzymes loosen the slimy parenchyma from the parchment covering. The beans are then dried, either by the sun or by mechanical dryers.