Also one of the traditional processing methods, the washed processing method is popular among the public for its brighter acidity and clean flavor perception.
The picked coffee cherries, after soaking and screening, will first enter the peeling machine and pectin removing machine to remove the exocarp, pulp, and pectin. If it is not cleaned, it will be put into the water tank in the next step, and through fermentation, microorganisms will decompose and remove residual pectin. Finally, it can be rinsed off and left to dry.
Since air-dried coffee is not as “tight-packed” as natural-processed coffee, the husks to the pectin are removed, and the coffee dries faster. Moreover, the fermentation of coffee in the tank generally only takes about 1-3 days. The total number of days, compared with the sun treatment method, greatly shortens the treatment time. Not being bound by the weather also improves the efficiency of processing. The influence of unstable factors is reduced, and the processing procedure is relatively stable, thereby ensuring the quality of raw beans.
This depends on the purchase of equipment, the construction of treatment plants, and the use of water resources, which means other costs. Washing with water can make the flavor of the coffee cleaner, and it may also wash away some good flavor substances, so the flavor of the coffee will be relatively less layered.
This treatment method is more common in countries and regions with relatively abundant water resources or less sunlight and higher humidity, such as Kenya and Colombia.
Processing steps: picking – soaking and screening – peeling and pulping – fermenting in a sink – rinsing – drying
Flavor profile: bright acidity, clean flavor, low richness
Advantages: less affected by climate, stable quality, low time cost
Disadvantages: the process is more complicated, the water consumption is large, some flavor is lost, and the direct discharge of waste liquid will damage the environment
Representative coffee regions: Kenya, Colombia, Central American countries