Coffee processing comprises a series of variable steps from harvest to a bean ready for storage and roasting. It can de divided into two major categories, wet and dry, which in their dealings with the coffee beans ultimately determine the potential final flavor of coffee.
Wet processing allows for the removing of unripe cherries by density, as unripe fruit floats and is subsequently screened. The ripe cherries’ skin and pulp is removed by using water pressure and they are sorted. In the next step the mucilage is removed through friction and the bean is washed while a final density sorting is performed. Beans are sun dried to a moisture level of approximately 12% and the drying process is finished mechanically to around 10%.
In dry processing, also referred to as unwashed or natural, cherries are directly sun dried without their outer layers being removed. Mechanical drying to reach the desired final moisture levels before storage or roasting is usually used.
For both processes a final milling is required, which will remove excess debris and prepare the coffee for a final grading.