The coffee cherries, just after the picking, have to be extracted for obtaining the beans. Extraction can be divided into two main methods:
Dry method: the results of this method are the so called natural coffees. If the picking has been made with the stripping method it’s important to wash all the cherries so to take off all the impurities and other foreign bodies (e.g. leaves, little branches, etc.) that could be mixed within the cherries. Usually the cherries can be sieved and then cleaned with a high pressure water jet, or can be plunged into water streaming basins. Just after the cleaning process the drying treatment takes place in putting the cherries under a sun bath so to dry. The drupes are stocked into cement farmyards and are moved and mixed so to have all of them under the sun bath. The drying process concludes into drying houses. When the drupes are completely dry the decorticate phase starts so to obtain beans free from skin, fleshes etc. At the end of that phase the beans have to be classified (for dimension and type) because they don’t have all the same quality.
Wet method: the results of this method are the so called washed coffees. The wet method is used mostly when the cherries have been harvested by picking. This process is a little bit more elaborated than the dry method but it guarantees better quality results. Just after the cherries have been picked they are put into water tanks to separate the matured cherries from the unripe and shrivelled ones. Then the cherries are put into a machine that extract the beans: because this process leaves some pulp around the beans, these ones have to stay two or three more days into water tanks so to separate completely from the leftover pulp . The last step is the drying phase: usually it’s made under sun bath (it’s the best methodology) but often some drying machines are used. The last phase is to clean the dried coffee from the pergamin (a sort of film that wrap up the beans) using hulling machines.
What are the differences between a washed coffee and a natural one?
A washed coffee has a more intense colour verging on pale blue. It’s due to the better silver skin removal process that the washed coffees have a superior quality: beans are more homogeneous and have better aromatic features. from the different producer countries Brazil mostly uses the dry method whereas Centre America, Kenya, Ethiopia and few others use the wash method.