Once coffee cherries have been picked, it is necessary to process the crop before they are ready to be packed and shipped off to roasters. Different processing methods impart different flavours and characteristics to coffees and some processes are better suited to some types of coffee. Today we are going to take a quick look at the various methods and discuss what they add to the beans.
Washed and semi washed coffees are generally said to produce better quality coffee. They are the most expensive methods due to the increased use of machinery and consumption of water during the process.
Fully Washed Coffee
For fully-washed beans, the picked cherries are put in water in order to separate them out. The ripe ones will sink, whereas the poor ones will float. The floating beans are then removed.
Then, the skin of the cherry and some of the pulp is removed from each individual bean by pressing it through a screen using a machine. Nevertheless, a lot of the pulp will still stick rigidly to the beans, so it is then necessary to either use machine processing or further water processing in order to remove the final pulp.
After the depupling process the beans are then washed, dried and packed.
Washed coffee allows the individual character of the bean to shine through. Unlike with a Natural Process, the washed method does not impart the flavour of the cherry pulp into the coffee bean.
Semi-washing beans involves fewer steps than the fully-washed method and is therefore a cheaper processing method.
Also known as 'wet hulling', 'Giling Basah' (from the Indonesian meaning 'wet grinding') or the 'pulped natural process'. This method tends to reduce acidity of coffee and makes for good espresso.
For this method, the outer skin from the cherries is removed using a machine, following which the coffee beans â€“ still with their mucilage attached â€“ are then stored and allowed to ferment. After this storage period the beans are then washed, dried and packed ready for roosting.
As you might expect, Semi Washed coffees offers a half-way house between the natural taste of Fully Washed whilst allowing the processer some of the ability to impart flavours similar to Dry Processing.
known as the unwashed or natural process. In this process, the newly harvested coffee cherries are sorted, and sun dried on concrete patios. The coffee is regularly raked over for even drying. This process can take up to 4 weeks to complete.
Once the drying process has been completed the cherries are then put through a hulling machine which removes the pulp in one step.
When done properly, dry processed coffee results in a smooth and heavy bodied brew. The method can be manipulated to impart different flavours into the coffee bean.