In this method, the coffee cherries are first separated according to their weight and size to ensure that a uniformity of ripe cherries prevails. Then the cherries are put into a wetmill, where the pulp is separated from the interior. After de-pulping, the next layer, the mucilage, is removed by washing in water. This is done for 12 to 48 hours in a fermentation tank filled with water. Now only the parchment skin and the underlying silver skin are left. To dry the coffee gently, it is then spread out on drying beds.
This method is a resource-intensive process that is often too expensive for farmers in poorer countries to consider.
In the picture above, you can see washed and natural processed beans after roasting. The difference can be seen in the silver skin in the center, which natural processed beans no longer have. While the washed beans still have the parchment skin in the groove.
Washed processing typically results in a clean cup profile with a tangy acidity.
