How a coffee is processed after harvest can have a significant effect on the resulting cup, so it has become an increasingly important part of how it is described and sold.
After harvest, coffee is taken to wet mill where they separate beans from the flesh. and dry the beans so they are safe for storage. There is no doubt that processing can have a massive impact on the cup quality of the coffee, and there is a growing trend for skilled producers to manipulate the process in order to yield specific qualities in the cup.
The Natural Process
As known as the dry process, this is the oldest method of processing coffee. After harvest, the coffee cherries are spread out in a thin layer to dry in the sun. Once the coffee is dried, the outer husk of skin and dried fruit are removed mechanically, and the raw coffee is then stored.
Natural process adds certain flavours to the coffee that is heavy in body, sweet, smooth, and complex. It is often used in countries where rainfall is scarce and long periods of sunshine are available to dry the coffee properly as in Indonesia, Ethiopia, Brazil, and Yemen.
The Washed process
The goal of washed process is to remove all of the sticky flesh from the coffee seed before it is dried. This process is more expensive than the others. After picking, the coffee cherry has its outer skin and most of the fruit flesh stripped off using a machine called a depulper. The coffee is then moved to a clean tank or through of water where remainder of the flesh is removed by fermentation.
The pulped natural process idea is to produce coffees with high cup quality using less water than in the washed process. After picking coffe is depulpe, stripping all of the skin and fruit flesh from the bean and then goes on to drying beds or patios. It is often sweeter than wet-processed coffees, has some of the body of a dry-processed coffee, but also retains some of the acidity of a wet-processed coffee. This type of processing can only occur in countries where the humidity is low and the coffee covered in the sweet mucilage can be dried rapidly without fermenting.
The honey process is very similar to the pulped natural but used in a number of Central American countries. The coffee is mechanically depulped, but the method uses even less water than the pulped natural process. With larger quantities of flesh being left on the beans there is a higher risk of fermentation and defect when the coffee is dried. Flavor profile of honey process coffee includes notes of chocolate, brown sugar, spice and cedarwood.