Often overlooked by coffee drinkers, the way coffee is processed after harvest can have a great impact on the taste of the final cup. In general, processing involves stripping the flesh of the coffee cherry off the seed, and drying the seed in preparation for transport. The difference here is how the flesh is separated from the seed.
The Natural process or dry process
This is the most traditional and economical way to process coffee. After harvest, the coffee cherries are laid out in the sun over a large area, such as an open patio to dry. Workers regularly turn the cherries to ensure an even drying process, and to avoid mould and fermentation. Better equipped plantations may use a drying table that allow better air circulation under the cherries. Once dried, the flesh can then be peeled off easily. As the flesh remains in contact with the seed during the drying process, coffee beans processed in this way may develop a fruity flavour, often described as various berries in the taste profile.
The Washed process or wet process
In contrast to the natural process, the washed process aims to remove the coffee flesh before the seed before it is dried. After harvest, the coffee cherries are placed in a depulper to strip off the flesh. The seeds are then immersed in water for the fermentation of the remaining flesh. Fermentation breaks down the remaining flesh, which can then be easily washed away. Finally, the cleaned seeds are placed on open patios or drying tables to be dried. As in the natural process, the seeds are constantly turned to ensure even drying. Coffees processed in this way often result in higher acidity and complexity. It is also generally described as “clean”, where objectionable flavours are not present.
The Pulped Natural process
This process is developed in areas where there are insufficient water to do use the washed process. Here, the coffee seeds are laid out to dry immediately after the depulping, skipping the fermentation and washing steps. The remaining flesh remains in contact with the seed while drying, imparting a level of fruitiness and sweetness to the final cup.
So there you have it, the three main ways of processing coffee. Do keep a lookout for the process the next time you try a single origin, and look out for those flavours!