The coffee that we enjoy so much is prepared from the roasted seeds of a fruit. What we call a coffee bean is in reality a seed nestled inside a coffee cherry. These cherries are at their sweetest when they are ripe. They should then be picked from the plant and processed as soon as possible in order to keep all their potential. It is necessary to process the coffee cherries to prepare the seed for roasting.
Processing coffee has two stages: the preparation stage and the dry milling. The steps followed during the preparation stage vary per region or even per farm. The main methods are dry process (also known as “natural”) and wet process (also known as “washed”). Nowadays it is in fashion to use a combination of both techniques, which is known as pulped-natural, semi-washed or honey. Maybe a small scheme will make it easy to understand.
I once wrote about the natural process, you can check it out here
I will write about the washed and semi-washed process in future posts.
In the preparation stage the coffee transforms from the cherry stage into the parchment stage. In the parchment stage the coffee beans are dry but still covered with a protective layer. The steps in this preparation stage will vary depending on the process method: Wet, dry or in between, but they all prepare the coffee cherry for the dry mill stage. The preparation stage is many times refers to as “wet milling” which is slightly misleading since in some of the processes there is actually very little water involved.
During the dry milling or hulling the dry skin (from natural process), parchment (from washed process) or different degrees of silverskin (from honey process) are removed to reveal the green been inside. Once the coffee has been hulled, the green bean has no more protection and should be sorted, packed and stored properly as soon as possible.
The way coffee is processed will have a huge impact on the flavour and cup quality of the coffee. It is very optimistic to think that the producers have in mind the end result when choosing a process method. For many producers, when processing coffee the goal is to make the coffee as profitable as possible. Producers take into account that some methods require more time, skills or natural resources than others when deciding how to process their coffee. A more recent factor determining the chosen process is climate change. Regions that traditionally produce certain amounts of washed and natural coffee are some years confronted with very wet harvesting seasons making it impossible to naturally dry the coffee, so all coffee will be washed. Other years it’s so dry in harvesting season that there is not enough water available to wash the coffee and only naturally dried coffee can be produced.