Coffee Processing Defined
Processing in coffee production refers to the methods used to transform freshly harvested coffee cherries into export-ready green coffee beans. Processing is a crucial step in a coffees journey from seed to cup, and it can have a profound effect on the final flavor of the coffee. This blog will introduce you to the four most common processing methods used by producers around the world.
Washed Process (AKA Wet Process)
In the washed process, a freshly harvested coffee cherry is sorted for ripeness, then mechanically depulped. Most of the fruit is removed during depulping, but some mucilage continues to cling to the seed. The next step, fermentation, naturally breaks down the remaining fruit’s grip on the seed. Fermentation times range from 12-36 hours, depending on weather. The coffee is then washed in fresh water to remove the last bits of fruit. Next the coffee is slowly dried on patios, raised beds, or in mechanical driers until it reaches 10-12% moisture.
Finally, the thin protective parchment layer is removed to reveal the green coffee bean that will eventually be exported and roasted. The washed method often produces clean, mild tasting coffee with good acidity and subtle flavor notes. Washed process coffee is common in Latin American and African countries, and less common in Indonesia.
Natural Process (AKA Dry Process)
A freshly harvested coffee cherry is laid out in the sun to dry. After the fruit is totally dry, it is removed. Finally, the thin parchment layer is also removed to reveal the green coffee beans that will eventually be exported and roasted. This method is inherently more risky and can often result in tainted flavors in the cup. Naturally processed coffees also rely on visual sorting for ripeness in contrast to water sorting in the washed process (ripe cherries sink, unripes float). As a result natural coffees often have more quakers, or underripe beans, then washed coffees. This method produces full bodied coffee with mellow acidity and ripe fruit notes. The natural process is most common in Brazil, Ethiopia, and Yemen.
Pulped Natural (AKA Honey Process)
The Pulped Natural process is a hybrid of the washed and natural processes. A freshly harvested coffee cherry is sorted, depulped, and then set out to dry with some of the fruit still clinging to the seed. When the coffee dries to 10-12% moisture, the parchment layer is removed and the green beans are bagged for export. Brazil is known for producing coffee with this method. This method is also common in El Salvador or Costa Rica, where it is called the Honey Process, or Miel in Spanish. Pulped natural coffees tend to have slightly more body and less acidity than their washed counterparts.
Wet Hulled (AKA Giling Basah)
The wet hulled method, also known as Giling Basah in the local language, is unique to Indonesia. It starts out like the washed process: A freshly harvested coffee cherry is depulped, fermented and washed. The coffee is then dried, but only to 30-50% moisture. At that point the parchment layer is removed revealing the still-wet green bean, hence the name wet hulled. The naked bean continues to dry until it reaches 10-12% moisture and is ready for export. This method of removing the parchment layer while the coffee is still wet causes a unique earthy flavor profile in the finished cup. Exposing the delicate wet green bean can also cause undesirable musty, moldy or vegetable flavors. When done well, wet hulled coffees have heavy body with low acidity and earthy flavors. This method is most often seen in Indonesia, especially Sumatra.
We always include the processing method on the labels of our single origin offerings. Check it out the next time you see our coffee on the shelf or in our online store. We also challenge you to try out different methods to discover their nuances and determine your favorite processing method.