How Does Washed Processing Affect Coffee Flavor? Bright and Clean Characteristics of Washed Coffee Beans

FrontStreet Coffee: Introduction to Washed Coffee Processing

Washed Method

In the washed processing method, coffee cherries are picked and processed to remove the outer layers, leaving only the beans covered by their inner parchment skin, which are then dried. This process involves several steps. First, fresh coffee cherries pass through a depulping machine that separates the outer skin and pulp from the beans. The beans are then washed with water and dried under shade canopies. The coffee beans are transported through water channels where they are separated by weight—lighter beans float to the surface while heavier, mature beans sink to the bottom.

The beans then pass through a series of rotating cylindrical sieves that separate them by size. After this separation, the beans are transferred to large fermentation tanks filled with water. Depending on various factors such as the condition of the beans, climate, and altitude, the coffee beans will remain in these fermentation tanks for 12-48 hours. The purpose of this step is to remove the smooth, mucilaginous layer (known as the mucilage or pectin layer) that still adheres to the parchment skin. Enzymes produced by natural fermentation of the beans in the tank will break down the mucilage layer. When fermentation is complete, the beans will feel rough rather than smooth. At this point, the beans are rinsed through another water channel. They are then ready for drying.

If coffee cherries are processed using the washed method, the depulped and fermented green beans must be dried to a moisture content of approximately 11% to be suitable for storage. These beans are still encased in their parchment layer (the inner skin), and can be spread out on patios or the ground for sun-drying with regular turning, or dried using large rotary dryers. Once the coffee beans are dried, they are known as "parchment coffee" and are packed into sisal or jute bags for export.

The washed process not only preserves the original flavor of coffee but also enhances its brightness, or acidity, as well as special fruity aromas.

Knowledge Point

Coffee beans are the fruit of the coffee tree, which belongs to the Rubiaceae family as a perennial evergreen shrub or small tree.

In Brief

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

Important Notice :

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