The coffee fruit/cherry can be subdivided in:
The term processing in specialty coffee refers to the methods and preparation used to turn fresh ripe coffee cherries into green beans (which will go through Roasting next). This includes removing the bean from the fruit/cherry (depulping), fermenting and drying the beans. This can be done in several different styles, the 3 most common methods being Natural, Washing and Honey processing and they have a big impact on the final flavor of the coffee.
Before actually processing the berries, there can be several steps of bean sorting. The cherries can be sorted by immersion in water where the spoiled cherries will float to the surface and the green/ripe cherries sink. It’s also frequent to see the use of air streams and sieves to remove dirt and undesired materials mixed with the beans.
Refers to any one of several technological variations where the parchment, pulp and skin are dried together with the bean. Also known as the dry process (or via seca in Portuguese), natural processing is most old school way to process coffee.
After harvest, the whole cherries are cleaned and placed on drying tables. The cherries must be regularly rotated by hand or with rakes to ensure even drying of the cherries. Depending on the strength of heat, like when using just sunlight, this process can take up to 4 weeks. Once the cherries are properly dry, the skin and dried fruit flesh are removed mechanically and the green coffee is stored and “rested” before exporting it.
Because the fruit sugars are drying into the seeds of the green coffee, the results are a heavy bodied, really sweet, fruity tasting coffees. The downside is that all this biomaterial increases the risk of over-fermentation the fruit during drying, which is why this method is divisive in barista’s opinions as it brings wild and wine-like flavors.
Also known as wet process (or via úmida in Portuguese), it refers to any one of several technological variations where the parchment, pulp and skin are separated (depulping) before drying.
The cherries are depulped with specialized equipment that uses water to facilitate the pulp separation. At this stage the seeds will still have a large quantity of remaining mucilage which needs to be removed. After depulping the beans are put to a water tank where fermentation process will remove the remainder of the fruit flesh. After the fermentation is ready, the coffee beans are washed to remove any leftover flesh and then it is ready to be dried. Drying in the washed process is done similarly as in natural process.
Because the fruits not drying/fermenting into the seeds and is completely removed before drying, the results are cleaner, acidic/brighter and light bodied coffee. In comparison to the dry process, the wet process is very costly. It’s commonly highly appreciated among roasters and baristas due to increased complexity and cleaner cup profiles. Many describe washed coffees to have white wine like flavors when compared to natural coffees. Many farmers or producers choose the washed process because properly done it reduces the risk of defects and it’s more stable way to process coffee.
The honey process is used commonly mainly in Central American countries such as Costa Rica and El Salvador. It refers to the method in which the parchment and a specific percentage mucilage are dried together with the seed, just the skin being totally removed. It was developed as a processing technique to enhance the flavor profile of the coffee.
Depending on how much mucilage is still attached on the coffee seeds before drying determines what type of honey process it is:
The pulped natural process, also known as the semi-washed process (or descascado/despolpado in Portuguese), was pioneered in Brazil. It’s pretty much the same principle of Honey processing: remove the skin and let the beans dry along with mucilage. The technique primary motivation is a speed up in comparison to the natural processing, which reduces the risk of over-fermentation.
This method combines the fine elegant attributes of washed coffees and the substantial body and fruit sweetness of a naturally processed coffee. It has some of the risk of drying and over-fermenting faults.