Washed Coffee Bean Processing: A Complete Guide to Benefits, Drawbacks, and Ethiopian Washed Coffee Flavor Profiles

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FrontStreet Coffee - Introduction to Washed Coffee Processing

Washed Method

First remove the skin of the coffee cherry, then remove the mucilage through fermentation or mechanical means, and rinse the softened mucilage from fermentation with large amounts of water. Afterwards, the coffee beans with parchment are mechanically dried (1-2 days) or sun-dried (3-16 days).

1. Bean Selection

The harvested fruits are placed in a water tank. At this time, mature fruits will sink, while unripe and overripe fruits will float and can be removed.

2. Pulp Removal

Use machines to remove the skin and pulp, leaving only coffee beans wrapped in parchment. At this point, the beans still have a layer of mucilage on the outside, and the washing process is designed to clean this mucilage.

3. Fermentation

The adhesion of mucilage is strong and not easy to remove. It must be placed in a tank for about 18-36 hours to ferment and decompose the mucilage. There are two fermentation methods: wet fermentation and dry fermentation. As the name suggests, the former adds water while the latter does not. During the fermentation process, the seeds and internal pulp undergo special changes, which is the step that most affects coffee flavor in the washed method. Some farms add hot water or enzymes to speed up fermentation, which negatively impacts quality and is not welcomed by specialty coffee enthusiasts.

4. Washing

Farms using the washed method must build washing tanks and be able to introduce continuous flowing water. During processing, the fermented beans are placed in the tank and moved back and forth, using the friction between beans and the power of flowing water to wash the coffee beans until they are smooth and clean.

5. Drying

After washing, the coffee beans are still wrapped in parchment with a moisture content of 50%. They must be dried to reduce the moisture content to 12%, otherwise they will continue to ferment, become moldy and spoil. The better processing method is sun drying, which takes 1-3 weeks but produces excellent flavor and is quite popular. Additionally, some places use mechanical drying, which greatly reduces processing time but results in inferior flavor compared to sun-dried coffee.

6. Hulling

Once dried, the beans can be stored in warehouses or sent to factories for hulling to remove the parchment and silver skin.

7. Selection and Grading

Manual selection typically uses conveyor belts about 1 meter wide, with several female workers sitting on both sides using visual inspection to remove defective beans. Some excellent farms even go through several rounds of selection until no defective beans are visible. Machine selection uses computer identification to remove defective beans, followed by grading procedures that divide coffee beans into several quality levels according to established standards. Good coffee enters the specialty coffee market, while poor coffee flows into the commercial coffee market.

Benefits of Washed Processing

Washed coffee processing can better highlight the unique characteristics of the coffee beans themselves. The quantity of defective beans can also be significantly reduced during the washing process, further improving the quality of coffee beans. Washing results in a cleaner taste without off-flavors and with charming fruit aromas. The color after washing tends toward blue-green or gray-green. Washed coffee has a clearer, brighter taste without off-flavors.

Knowledge Point

According to the degree of mucilage retention, honey processing is further divided into yellow honey, black honey, etc.

In Summary

FrontStreet Coffee is a coffee research hall that enjoys sharing coffee knowledge with everyone. We share without reservation only to help more friends fall in love with coffee. Every month, we hold three low-discount coffee events because FrontStreet Coffee wants to let more friends drink the best coffee at the lowest price. This has been FrontStreet Coffee's mission for the past 6 years!

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