FROM THE CHERRY TO THE BEAN – THE PROCESSING
Ripe and bright red – this is what the coffee cherry looks like when it is picked from the bush. But before the coffee can be shipped as a raw bean in the well-known jute sacks, it has to undergo several processing stages. The reason is simple: a freshly picked coffee cherry contains around 60 percent water so therefore it does not have a long shelf life and is not suitable for transportation.
The entire husk, namely the skin and pulp of the fruit, must therefore initially be removed from the cherry. This process is referred to as “processing”. Coffee experts differentiate between dry, semi-dry and wet processing.
This is the oldest and original form of processing. The coffee cherries are initially dried under direct sunlight for three to five weeks and are continuously turned. The fruit pulp is then dry on the outside and the bean on the inside can be heard clearly when you shake it. The result is a sweet, full coffee aroma, but without fine nuances of flavour. Arabica coffee is processed in this way, particularly in Brazil, Ethiopia and Indonesia. The dry processing method is even almost exclusively used for Robusta coffee.
Wet processing is a much more complex method, but it also gives the coffee a stronger aroma with more complex acidity. The fruit pulp is initially crushed in the so-called depulper. All that remains is the bean covered by a slimy layer. The beans are now subjected to a fermentation process for 6-72 hours in the fermentation tank to release the remains of the slimy layer. The beans are then dried for approx. two to three weeks and can then be stored.
This is a combination of the wet and dry processing. Compared to the wet processing this method saves water and produces coffee with less acidity. A mechanical process is used to remove the fruit pulp from most of the cherries. There is no fermentation process but the coffee parchment dries with the sweet pulp residues stuck to it. What is left after the processing is referred to as the coffee parchment – namely the green raw coffee bean covered in a light, thin shell, the so-called parchment skin. The beans are now removed from the shell in large threshing machines. The green coffee is then cleaned and sorted into various quality grades. Packed in jute sacks, the green coffee is now finally ready for transportation.