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

FrontStreet Coffee: How Washed Processing Shapes Coffee Flavor

The Washed Method

In the washed process, coffee cherries are picked and stripped of their outer layers so that only the beans, still wrapped in their inner parchment skin, are left to dry. The method unfolds in several steps. Fresh cherries first pass through a depulping machine that separates the skin and pulp from the beans. The beans are then washed with water and dried under shade canopies.

Next, the coffee travels along water channels, where it is separated by weight: lighter beans float to the surface while heavier, denser, mature beans sink to the bottom. The beans then pass through a series of rotating cylindrical sieves that sort them by size. After that, they are transferred to large fermentation tanks filled with water.

Depending on factors such as the condition of the beans, the climate and the altitude, the coffee will sit in these tanks for 12 to 48 hours. The purpose of this step is to remove the slippery, mucilaginous layer - the mucilage, or pectin layer - that still clings to the parchment. Enzymes produced by the beans' natural fermentation break the mucilage down. When fermentation is complete, the beans no longer feel smooth but rough. At that point they are rinsed through another water channel and are ready for drying.

Washed coffee must be dried down to a moisture content of roughly 11% before it can be stored safely. The beans are still enclosed in their parchment layer (the inner skin), and they can be spread out on patios or on the ground to sun-dry with regular turning, or dried in large rotary dryers. Once dry, the coffee is known as "parchment coffee" and is packed into sisal or jute bags for export.

The washed process does more than preserve a coffee's original flavor: it sharpens its brightness, or acidity, and lifts its distinctive fruity aromas.

Did You Know?

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 without reservation simply to help more friends fall in love with coffee. Every month we hold three discounted coffee events, because FrontStreet Coffee wants to offer the best coffee at the lowest prices to more friends. That has been FrontStreet Coffee's mission for the past six years.

FrontStreet Coffee Recommendation

The clearest way to taste what washing does is an Ethiopian washed coffee, and FrontStreet Coffee's Washed Gedingding Cooperative beans are a perfect example. Grown by the Gedingding processing team in the Woka area, they show jasmine florals and vivid citrus acidity at their most transparent; a medium-light roast adds green tea and honey notes on top. It is a lovely pour-over, cold brew or espresso base.

For a variation on the theme, try FrontStreet's Kenya Cherry Tomato. Kenyan producers are masters of double washing - here a 72-hour K72 regimen - which pushes the juice-like quality to the extreme. Expect cherry tomato, dark plum, snow pear and black plum, with a sweet-and-sour, mouth-filling character that shows just how clean and expressive a washed coffee can be.