How coffee processing affects the taste of your cup
Processing coffee is the method of removing the outer fruit (cherry) to expose the green beans. The method adopted by each farm is based on many factors, including water supply and climate. Their primary objective is to ensure the least possible incidence of defects and optimal flavour.
There are heaps of experimental processing methods (like watermelon processing from Riverdale Estate or ‘Fermentum Naturalis 46’ from the Pura Cepa Project), but the three most common methods are:
Wet or washed process
Cherries are soaked in large flotation tanks of water where unripe fruit floats to the top. The ripe cherries are taken for pulping where the outer skin is removed but still covered in mucilage. The coffee is then placed in troughs of water where remaining flesh is removed through fermentation. The coffee is then washed again to remove remaining debris and dried in the sun. Washed coffees produce a cleaner, brighter taste with higher levels of acidity.
Dry or natural process
The fruit is sorted to remove unripe cherries. The outer skin of the ripe cherry is then mechanically removed. The stripped fruit is then placed on wire racks or concrete beds and allowed to dry in the sun. The moisture from the pulp evaporates and the natural sugars are absorbed by the beans. Each cherry becomes shrivelled and dried. The skin and mucilage are then removed by husking machines. Coffee processed in this way develops bold, fruity sweet flavours with a full body.
Pulped natural or honey process
This process combines wet and dry methods. It begins by soaking the cherries in flotation tanks. The ripe cherries are then taken away and the skin removed by a mechanical depulper. The sticky mucilage is still on the coffee and then left in the sun to dry. Coffee cherries processed in this method have the clean fruity taste of natural coffee without the acidity of a washed coffee.