Processing coffee refers to how the coffee cherries are treated post-harvest. Several farms are experimenting with new and exciting methods, but the two main styles of processing are Natural and Washed.
A quick disclaimer before class today: natural does not mean ‘dirty’, and washed does not mean ‘clean’. Here we go!
Natural process is the most traditional and oldest form of coffee process, and is interchangeable with the terms Dry, Sun dried
This method is common in areas with restricted access to water due to low humidity and infrequent rain, such as Ethiopia and Yemen. It’s far less common than the washed method
because of being labor intensive and unpredictable environmental factors. Coffees processed this way boast more fruity and fermented flavors because the bean has more time to absorb the natural sugars from the cherry as the sun breaks down the fruit. The bean and the cherry exchange molecules and flavor is seeped into the seeds, lending distinctive fruity notes, specifically berry.
Washed processing entails that the fruit of the cherry is removed BEFORE the beans are dried. A machine called a depulper removes the flesh of the cherries, the beans are transferred to a specialized cleaning tank, and any remainder of fruit is removed using fermentation. Fermentation promotes the separation of any residual pectin still stuck to the bean, but it must be closely monitored, as too much or too little time can dramatically impact flavor once the bean is roasted. After fermentation, the bean is washed again and left out in the sun to dry up any moisture.
Washed processing is far more expensive than natural, as it requires more equipment and trained staff, but the risk that a lot will spoil is greatly reduced. Removing all of the fruit before drying allows the intrinsic flavors of the bean to shine through. This produces a cleaner, vibrant, more complex roast due to slightly higher acidity. Fruit notes are still found, however berry notes specifically are far less common. Expect more but, chocolate, spice, caramel, and maple flavors from washed processed coffees.
“K.I.S.S...Keep It Simple, Stupid.” -Michael Scott (The Office)
Whole coffee cherry dried in the sun, then hulled and stored.
Cheaper, but more prone to unforeseen risks.
Berry, fruit-forward flavors.
Fruit of the cherry is removed and beans are washed before being sun dried.
More expensive due to equipment costs, but less risk for spoilage.
More complex flavors like nut, chocolate, and spice due to higher acidity.
Until next time, thanks for drinking and learning with us!
Written by: Sam Raph