Semi-washed, honey process, pulped natural, wet-hulled.
As each has its own merits and intricacies, this article will focus on two main styles of semi-washed methods. 'Wet-hulled' and 'Honey'/'Pulped natural'. The basic steps of all semi-washed processed coffees include; pulping, drying, parchment removal, cleaning and grading.
Honey and Pulped Natural coffee are the same process, just different names. Once ripe coffee cherries have been picked, the outer fruit is removed, but the sticky flesh layer and the mucilage are left intact. The sticky beans are then out out to dry like an 'unwashed' coffee. Once dried, the parchment is removed via hulling and the beans are then cleaned, graded and sorted.
Wet-hulled coffee is specific to Indonesia. It is different from any other method in the world. Once ripe coffee cherries have been picked, the fruit is removed as soon as possible. This is referred to as 'pulping' or 'milling'. The mucilage layer is then washed off the beans. The coffee is then raked across a patio for drying. Once the coffee has reached approximately 30% moisture, it is put through the hulling process to remove the parchment layer. The beans are still malleable at this high moisture content and the beans can often be disfigured by the huller. The reason this is done is because of the high humidity in Indonesia. The farmers and millers are afraid to leave their coffee outside drying for too long, so by removing the parchment skin earlier than usual, the beans are more exposed to the air and therefore dry quicker.
Each seemingly insignificant one of these steps can ruin coffee. If under or over-ripe cherries are picked, the rest is pointless. If the coffee is not pulped immediately after picking, the coffee will taste fermented. If the coffee is left in a big pile to dry it will go mouldy, so the coffee must be dried in a thin layer to ensure even drying. The more we understand about the coffee process, the more we appreciate good quality coffee when we get it.