What's the Difference Between Natural, Washed, Semi-Washed, and Semi-Dry Coffee Processing Methods? Do Washed Beans Have Silver Skin?

Professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat public account: cafe_style)

We all know that coffee-producing regions are mainly divided into three major coffee regions: the Americas, Asia, and Africa. The coffee flavors from producing countries within each major region are very different and each has unique characteristics. Many customers often visit FrontStreet Coffee stores to discuss related coffee knowledge, and FrontStreet Coffee has found that some coffee enthusiasts are particularly interested in special coffee bean processing methods. Therefore, FrontStreet Coffee plans to talk about related coffee bean processing methods with everyone today.

The Influence of Processing Methods on Coffee Flavor

Generally speaking, the flavor of coffee beans largely depends on their origin, which is what FrontStreet Coffee often refers to as altitude, terrain, and climate. Another part depends on their processing method. FrontStreet Coffee takes FrontStreet Coffee's washed Yirgacheffe and FrontStreet Coffee's natural red cherry from Ethiopia's Yirgacheffe region as examples. Coffee beans processed using the washed method have a very clean and bright taste, but there's also a shortcoming: the mouthfeel can be somewhat thin. Coffee beans processed using the natural method have more intense body, aroma, and sweetness compared to washed processing. Therefore, when you taste FrontStreet Coffee's washed Yirgacheffe coffee beans, besides the subtle jasmine floral notes, there are also typical African lemon and citrus tones, while the sweetness of FrontStreet Coffee's natural red cherry becomes more apparent as it cools, with acidity leaning toward berry flavors.

Washed Processing Method

According to FrontStreet Coffee's understanding, the washed processing method is generally more commonly used in Central America, especially in areas with abundant water resources. The typical washed process is: first put coffee fruits into water tanks or buckets for screening, removing unripe coffee beans or debris, because defective beans can greatly affect the flavor of brewed coffee. Then use a depulper to remove the skin and pulp from the selected coffee beans, and place the depulped coffee beans in fermentation tanks to remove residual mucilage and membrane. Finally, the cleaned beans are dried, and the processed green coffee beans have a moisture content of about 11-13%.

Therefore, FrontStreet Coffee believes that the biggest advantage of the washed method is that all coffee beans are placed in water for screening at the beginning, and immature and defective beans are continuously removed throughout the process, so the quality of washed green beans is relatively high, and the appearance of washed coffee beans is also better than general natural beans. However, every processing method has its pros and cons. A major disadvantage of washed processing is water waste, and the washed processing method is more complicated than general processing procedures. During the fermentation process, coffee beans can easily absorb fermentation flavors, causing excessive acidity and becoming inferior beans. If left unmanaged in fermentation tanks, microorganisms can change, leading to reduced green bean quality. According to FrontStreet Coffee's understanding, to extract one kilogram of green coffee beans, 50 liters of fresh water are needed for washing operations. This is almost an impossible task in some water-scarce coffee-producing countries. The washed method requires extensive machinery for various operations, which is also a heavy burden for coffee farmers in some countries.

Natural Processing Method

African countries such as Ethiopia more commonly use the natural method. The natural method involves drying coffee fruits naturally after harvest, turning the originally bright red coffee beans into black coffee cherries. Coffee beans processed through this procedure will have significantly reduced moisture content to 11-12%. The natural method is very simple—just spread the harvested coffee beans evenly in open-air drying areas and dry them in sunlight for several days. To ensure uniform drying of coffee beans and avoid fermentation, the beans need to be turned frequently during the drying process. Natural processing is somewhat similar to China's method of sun-drying rice grains.

Of course, the natural processing method also has its advantages and disadvantages. The advantage of the natural processing method is its low cost, simple operation, and no need for complex equipment, so almost all coffee-producing countries in the past used this method to process green beans. However, the biggest disadvantage of this processing method is its dependence on weather conditions, longer processing time, and it's easy to mix in too many defective beans or impurities. According to FrontStreet Coffee's understanding, countries that maintain the natural processing method include Brazil, Ethiopia, Yemen, Bolivia, and others, among which Ethiopia's Harar region and Yemen Mocha are famous natural coffee beans.

Hybrid Processing Methods

Perhaps everyone now has a thorough understanding of traditional natural and washed processing methods, but coffee bean processing methods are far more complex than everyone thinks. Smart coffee farmers have developed semi-washed and semi-natural methods based on these two processing methods and natural environmental conditions.

The semi-natural processing method, as FrontStreet Coffee mentioned in the text above about the natural method, is an improvement on the old natural method. First, freshly harvested coffee beans are soaked in large water tanks for screening, removing defective beans and impurities, then machines are used to remove the pulp and outer skin while retaining the inner skin part. Finally, the coffee beans still covered with inner skin are sent to drying fields for natural drying. During the natural drying period, the coffee beans are still turned frequently to ensure even dehydration of the green coffee beans and avoid over-fermentation. Coffee beans processed with the semi-natural method are stored with their inner skin for a period before export to allow the coffee flavor to mature, and the inner skin is removed from the coffee beans just before export. This processing method is very popular in Brazil.

The semi-washed processing process involves first screening coffee fruits in water tanks to remove floating defective fruits, then using a depulper to remove the skin, pulp, and part of the mucilage layer, followed by washing for one hour. Due to the short soaking and fermentation time, mucilage is not easily completely washed away, and some mucilage remains on the bean shell. At this point, the processed coffee beans are spread on drying fields to dry, preferably using well-ventilated African raised beds.

Has everyone noticed that the processing method of semi-washed processing is very similar to the semi-natural processing process mentioned by FrontStreet Coffee? In fact, the semi-natural processing method and semi-washed processing method refer to the same processing method, because both processing methods have corresponding natural drying and washing processes, so they are collectively called the pulped natural method.

Brazil's Semi-Natural Processing Excellence

Therefore, water-scarce countries like Brazil generally use the semi-natural method to process coffee beans. Brazil's use of the semi-natural processing method has also brought distinctive coffee flavors to Brazilian coffee beans. Take FrontStreet Coffee's Brazil Queen Manor on FrontStreet Coffee's bean list as an example—this FrontStreet Coffee Brazilian coffee bean uses the semi-natural method.

FrontStreet Coffee considered that this FrontStreet Coffee Brazilian coffee bean has lower moisture content and harder bean texture, so a medium roast was adopted. Additionally, this FrontStreet Coffee Brazilian bean has strong heat absorption, so the roasting time must be very well controlled to highlight the aroma and body of this semi-natural processed coffee bean. For brewing, FrontStreet Coffee uses the common three-stage method, with a Hario V60 dripper, water temperature of 90°C, dose: 15 grams, brew ratio: 1:15, grind size: medium-fine (BG#6S).

FrontStreet Coffee typically starts with 30 grams of water for a 30-second bloom, then pours in a circular motion with small water flow to 125 grams for segmentation, continues pouring to 225 grams when the water level is about to expose the coffee bed, and stops pouring. When the water level is about to expose the coffee bed, remove the dripper (timing starts from the bloom), with an extraction time of 2'00".

When tasting this FrontStreet Coffee Brazil Queen Manor coffee, you can clearly feel the sweetness brought by the semi-natural processing method, subtle lemon aroma, and rich Brazil nut flavors from the Americas region, with distinct dark chocolate flavors in the finish. The overall experience is quite rounded—a coffee bean that can represent the overall characteristics of Brazilian coffee while also demonstrating its unique lively character.

For more specialty coffee beans, please add FrontStreet Coffee on WeChat (FrontStreet Coffee), WeChat ID: kaixinguoguo0925

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473