What is the Washed Processing Method? An Introduction to Washed Coffee Bean Processing and Flavor Characteristics

Understanding the Washed Coffee Processing Method

The washed processing method refers to the process of transforming harvested coffee cherries into raw coffee beans. The invention of the washed processing method stemmed from the crude techniques of traditional natural processing, which resulted in high defect rates. To pursue better coffee bean quality, producers began exploring ways to stabilize the final product during processing, gradually developing this processing approach.

The structure of a coffee cherry can be divided into skin, pulp, mucilage, parchment, silver skin, and seed—the coffee we drink comes from the innermost seed. The most common natural processing methods include washed and natural, with some growing regions adopting honey processing and wet-hulling methods adapted to local conditions. With advances in production technology, numerous innovative processing methods have gradually emerged, incorporating different operations based on these foundations, such as anaerobic natural processing, carbonic maceration, enzyme washing, and more.

Traditional Natural Processing

Traditionally, coffee cherries are spread directly on the ground to dry after harvesting until they reach a raisin-like state, after which machines are used to remove the outer hulls to obtain the inner beans. In coffee-growing regions of the African continent such as Ethiopia, Kenya, and Rwanda, where sunlight is abundant, this natural processing method has traditionally been employed. However, due to the crude techniques, coffee beans are often thrown directly onto muddy ground or rooftops for drying, making the coffee susceptible to absorbing earthy flavors from the ground or experiencing uneven heating that leads to over-fermentation, ultimately affecting coffee quality.

The Rise of Washed Processing

Since the introduction of the washed processing method in the 19th century, many coffee-growing regions in the Americas, particularly countries with abundant water resources, have abandoned natural processing in favor of washed processing, hoping to improve coffee quality through this method. Today, washed processing still accounts for a significant proportion worldwide. Let's examine the specific steps involved in the washed process.

The Washed Processing Steps

Before washing, coffee beans typically undergo floatation selection. Freshly harvested cherries are placed in water, and the buoyancy of water is used to separate out underripe cherries. Then, a pulping machine is used to remove the cherry's skin and pulp. At this stage, the coffee beans have a slippery texture, and production workers pour them into fermentation tanks to sit overnight. During mucilage fermentation, acidic substances are produced that cause the mucilage to decompose and detach from the beans.

After fermentation is complete, some mucilage still remains on the parchment coffee, so it needs to be brushed with tools for 30-60 minutes while running water helps completely clean away any remaining pulp. Specialized channels combined with flowing water can remove low-density, poor-quality beans. The high-quality coffee beans are then drained of water and spread on drying racks or raised beds to dry. Finally, once they reach the target moisture content, they can be packaged and stored.

Advantages of Washed Processing

Because multiple steps in the washed process can eliminate defective beans, it significantly reduces the defect rate of coffee and results in more stable quality. Without pulp remaining on the exterior during drying, the flavor profile exhibits vibrant acidity with higher cleanliness, highlighting the unique characteristics of a single origin. Therefore, to understand the "terroir" or "regional flavor" of a growing region, FrontStreet Coffee suggests starting with their washed batches.

Washed processing is a method that FrontStreet Coffee particularly appreciates. Our bean menu features dozens of coffee beans that have undergone washed processing. Here, FrontStreet Coffee will introduce an Ethiopian Yirgacheffe Banko Gotiti coffee bean to help you understand the characteristics of washed coffee beans.

Banko Gotiti Cooperative

The Banko Gotiti Cooperative was originally part of the Worka Cooperative under the Yirgacheffe Coffee Farmers Cooperative Union (YCFCU), which consists of 26 cooperatives with 45,000 members. Later, due to their mature washed processing skills, they became independent in 2012 and have since become a well-known team. In 1972, Ethiopia introduced washed processing technology from Central and South America. Cooperative members uniformly sort, clean, ferment, and remove pulp and mucilage from the purchased coffee cherries, then place them on raised beds to dry. Each step must be properly handled to ensure the quality of the final coffee product.

The Impact on Yirgacheffe Coffee

The washed processing method has transformed Yirgacheffe coffee from its previous inconsistent quality. Light to medium roasting particularly preserves Yirgacheffe's fresh citrus notes and elegant white floral aromas, resulting in an overall flavor that is bright and delicate. Consequently, Yirgacheffe became independent from the Sidamo region and has become a renowned growing area in today's coffee world.

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