The technicians start the washing process immediately, since delay can cause fermentation of the sugary coating surrounding the bean and ruination of the coffee flavour.The beans are first thrown into a deep tank. The best cherries sink to the bottom and pass through a machine that removes their skin. The technicians remove any floating cherries and process them in the same way as the others for the cooperative to sell on the domestic market for less than specialty-coffee price. The beans are fed through one of the cooperative's three de-skinning and selection machines to remove their skins and most of the sugary coating before running the individual beans through a vibrating colander.
The colander separates the very highest quality Grade A beans from those labeled Grade B; the two grades are sent separately down the hill in a water chute with a 1% gradient.This process allows for further separation of beans based on quality, with around 15 tanks available at the bottom for capture of the different types. The beans are kept submerged, two days for the best and 15–20 hours for the lesser beans, which causes a small amount of fermentation to convert the remainder of the sugar without significantly impairing the flavour.
Washed beans drying on racks
The technicians wash the beans several times to remove the remains of the skin and coating and put them out on shaded racks to dry.Cooperative employees turn the beans regularly as technicians spot and remove bad beans. A longer drying process of up to two weeks in the sun follows (with provision for quick covering in the event of rain), again with constant turning. This last process reduces the water content of the bean from 40% to 12%.
