What is wet processed coffee/washed coffee? Why is it popular?
After harvesting, coffee fruit will undergo processing to separate the kernels. There are 3 processing methods used most commonly today are dry, wet and honey. So, What is wet processed coffee? The process of implementation and advantages and disadvantages of the wet processing method. Let’s find out!
I. What is wet processed coffee?
Coffee processed by the wet method is called wet processed or washed coffee. The wet method requires the use of specific equipment and substantial quantities of water.
In other words, this is a complex processing process with stages: removing the meat surrounding the coffee beans; fermenting coffee beans; drying to obtain green coffee beans.
Removing the flesh in the coffee berries before it is dried helps to minimize risks compared to coffee fruit drying (such as further fermentation); resulting in higher-value coffee beans. .
Compared to dry processing method; wet processed coffee requires more complicated process and more stringent technical requirements.
II. Wet processing process of coffee beans
Wet processing of coffee beans includes the following 4 stages:
2.1. Sorting and processing coffee fruits
Post-harvest coffee is put into the water tank to remove damaged fruits emerging with other impurities; such as branches, leaves, mud mixed with ripe fruits …
2.2. Remove the flesh (fruit skin)
After washing and sorting, people will remove the flesh of coffee cherries from beans. Particle removal is performed using a Depulper shelling machine.
After that, these beans are transferred to a clean water tank or water trough so that the meat sticks on the fermented beans and is removed.
The meat of coffee has lots of pectin and sticks to the beans. This fermentation process will destroy the structure of coffee remains; causing them to be washed away with water. Each manufacturer usually uses different amounts of water during fermentation.
The fermentation time of coffee will depend on many factors. Especially, the height and the surrounding temperature. In other words, The higher the temperature, the faster the fermentation process takes place. However, if left on the wool bean coffee for too long; bad flavors will penetrate the beans.
In fact, to check if the fermented coffee is reached; some manufacturers use the way to wash coffee beans between two fingers. If the surface of the particle feels smooth, there is friction and making a squeaking sound, the process is complete. Others test by plugging a long tree into a fermenting box. When the tree is upright because it is supported by water containing a lot of colloidal Pectin; the fermentation is completed.
2.4. Clean and dry
After fermentation, coffee is washed to remove impurities on the beans. Then, people bring coffee beans spread out exposed to the sun. During drying, regularly stir the coffee to dry evenly; avoiding fermentation and mold.
In the case of lack of sunlight or increased humidity, some manufacturers will use a dryer to dry the beans; reducing the moisture content of the grain to 11% – 12%. However, the taste of a cup of sun-dried coffee is better than machine-dried coffee.
III. Characteristics of wet processed coffee.
With the wet processing method; the coffee bean must undergo fermentation by the enzyme itself or with the participation of the enzyme system of microorganisms. Therefore, helping to preserve the maximum amount of acid in the coffee bean pure. Thereby ensuring the acidity of the natural characteristics of each type; so create a taste that is popular among coffee connoisseurs.
In order to carry out the wet processing method; the operator must be knowledgeable about the berries. Moreover, it is necessary to closely monitor the fermentation process to avoid the formation of unwanted flavors due to fermentation exceed. At the same time, this method is also quite expensive: requires high cost, uses many machines and large amount of water.
IV. What type of coffee should use wet processing method
Normally, the wet processing method of coffee is usually applied only to high-quality Arabica coffee lines. There is also Typica or Bourbon and most of the Specialty Coffee are popular in countries of Central and South America or East Africa.
Coffee processed by this method is usually more expensive; while coffee with low economic value is less likely to use this method. For example, Robusta coffee is much more acidic in Arbica coffee; when combined with wet processing will leave a very bitter sour taste, uncomfortable sensory should most be processed dry.