Visiting the washed coffee process with K-Agriculture Factory


The washed coffee process is a topic that many individuals and businesses pay attention to because it is one of the most popular coffee processing methods in many countries. In the following article, with K-Agriculture Factory, we will explore the washed coffee process in detail.

See more: Vietnamese coffee production process

Washed Coffee Process – Overview

The washed coffee process is one of the most widely used coffee processing methods in the world. The below information will explain what the washed coffee process is, which countries use it, and which coffees are processed by it.

Definition of the washed coffee process

The washed coffee process is a post-harvest treatment that removes all of the pulp before it is dried. Specifically, the washed coffee process is a series of stages from the time the coffee is harvested, sorted, pulped, soaked to ferment, and finally, the beans are dried under sunlight to achieve a humidity of about 10-12%.

Distribution of the washed coffee process


Distribution of the washed coffee process

The washed coffee process is popular around the world include:

  • The washed coffee is a staple of some countries that specialize in cultivating high-quality Arabica varieties, such as Brazil, Ethiopia, Indonesia, and Yemen. The product quality is highly appreciated and extremely famous in the international market.
  • Premium Arabica from Colombia or Arabica products in Central and South American or African countries such as El Salvador, Tanzania are also applied in the washed processing method.
  • Other coffee exporting countries such as Ecuador, Jamaica, and Costa Rica also use the washed coffee process to increase the value of coffee beans.
  • In Vietnam, the washed coffee process is also applied by some raw material factories, especially in Cau Dat – Lam Dong and a part in the Central Highlands.

Because these countries are all strong in exporting coffee, they often use this method to process coffee, especially Arabica, to maximize their profits from coffee.

Characteristics of washed coffee beans

Coffee used for the washed process is usually high-quality coffee like Arabica.

  • Types of coffee used washed process

Normally, the washed coffee processing method is applied to Arabica coffee varieties such as Typica or Bourbon with high grain quality to maximize the flavor potential.

Coffee processed by this method is usually more expensive, so coffees with low economic value are less likely to use this method. Typically, Robusta coffee beans have a much higher acid content than washed Arabica coffee beans. When combined with the washed coffee process, there will be a very harsh sour taste and unpleasantness in terms of organoleptic, so most of them are in a dry process.


Types of coffee used washed process

  • Purpose of the washed coffee process

The main purpose is to remove all the outer skin of the coffee bean before it is dried. This minimizes the risk during the drying process, resulting in higher-value coffee beans. However, this method is often more expensive than others.

  • The taste of washed coffee beans

Compared to other treatments, washed coffee beans have higher acidity, sweetness, depth, and have been described as a cleaner cup. “Cleanliness” is used to indicate the absence of negative tastes such as unusual bitterness or long-lasting flavor in the oral cavity after drinking.

Washed Coffee Process – Steps and Requirements

The washed coffee process is a long, demanding process that is followed by strict requirements to maximize the farming efficiency and the quality of the coffee beans.

Careful preparation for the washed coffee process

Before coffee is put into the washed coffee process, coffee beans need special care to ensure quality.

Ways to take care of washed coffee beans


Ways to take care of washed coffee beans

To have the best quality coffee products, the first step must be to manage the coffee garden well according to criteria such as climatic conditions, soil, fertilizers, and pesticides. Depending on different types of coffee beans, there are many ways to have the best care to produce healthy seedlings and satisfactory coffee beans.

Ways to harvest washed coffee beans


Ways to harvest washed coffee beans

The selection of ripe red berries during the picking process takes more steps but will produce high-quality products. Stripped harvesting should be avoided as it will not be possible to distinguish between ripe or unripe or defective fruit.

  • Picking only the ripe red berries. Fully ripe berries can run smoothly through the washed coffee process and will give off their absolute aroma during roasting. This will be highly appreciated by customers.
  • Green fruit has a grassy or musty smell, reducing product quality and brown, rotting, or fermenting seeds also should be avoided. 

Fresh coffee beans need to be immediately transported to the factory for processing as soon as possible, avoiding fermentation.

Ways to choose washed coffee beans


Ways to choose washed coffee beans

At the receiving time, processors should empty the cherries from the bags and take samples to assess quality. If there are too many green or fermented or rotten berries (more than 10-15%), this coffee should not be processed as it may spoil the entire batch. The classification of defective particles in the later stages is time-consuming, expensive, and not necessarily highly efficient. Poorly fresh fruit will be discovered by customers during roasting and tasting.

Steps in the washed coffee process

The washed coffee process is a coffee processing process consisting of 4 main stages: sorting, pulping, fermenting, and drying. This is a complex method that requires professional knowledge and experience in coffee, as well as specialized equipment, and consumes a considerable amount of water. If done correctly, the quality of the beans is better developed in this technique and results in more uniform green coffee beans.

Step 1: Sorting

After picking, all coffee beans will be put into a large water tank to remove impurities like branches, coffee leaves, and mud mixed with soil.

The best screening is to put the coffee in metal sieves, discharge the water, and put in a siphon to remove green berries or light impurities. 

  • Damaged, shriveled, seedless, or wormed berries will create holes, causing them to float onto the surface. 
  • The remaining fruits that meet the requirements will be denser and heavier than water, so they will sink to the bottom. 

However, in this process, there will still be some sand, rocks, metal, and other heavy objects that will sink to the bottom of the tank and will be separated later.


Step 1_ Sorting

Step 2: Pulping 

This is an important step in the washed coffee process because it directly affects the taste of the finished coffee beans. People put the coffee beans into a depulper – in which the coffee cherries will be friction with the rotating cylinder. The outer skin (and part of the mucilage) of each cherry is quickly separated, leaving the bean still enclosed in mucilage. This process needs to happen quickly to avoid fermentation affecting the taste. The coffee beans need to be separated from their outer skin before being sent further to the aqueducts.

An interesting thing is that the outer skin after being pulped can fertilize coffee plants.


Step 2_ Pulping

Step 3: Fermentation

This stage consists of two main steps: biological fermentation and oiling by machine. Biological fermentation can be in a siphon, tanks, using or not using microorganisms while oiling by machine methods can use washing troughs or viscous mixers for washing. 

The mucilage is the remains of the outer skin and the pectin layer of the husk. This is the flesh of the fruit and is quite “stubborn” that cannot be removed by normal milling. Natural fermentation of coffee cherries as well as the participation of microorganisms will promote rapid decomposition of the mucilage without much mechanical work. 

#1: Biological fermentation


After removing the outer skin and other impurities, the coffee is placed in a water bath or siphon for 12-16 hours depending on the outside temperature so that the flesh that remains on the beans is removed. The higher the temperature, the faster the fermentation. But if the coffee is left to ferment for too long, bad flavors will absorb the beans.

The flesh of the coffee has a lot of pectins and sticks to the beans. The fermentation process helps to destroy the structure of the remaining flesh, allowing this layer to be washed away with water. The amount of water used in processing is usually in a 1:1 ratio. This is a very important step in the washed coffee process because it will greatly affect the taste of coffee later.

The fermentation process must be carefully monitored to ensure that the coffee is free of undesirable flavors.

When does fermentation end?

There are many methods to check whether this process is completed. Visually, there is no longer a slimy, slippery feeling, there is a feeling of “gravel” and the roughness of the husk. To achieve this, the coffee must be raked and stirred by hand or machine (often called a demucilager) so the friction between the beans helps to thoroughly remove the mucilage around the beans. When fermentation is complete, the coffee is thoroughly washed with clean water again.

#2: Oiling by machine


Step 3_ Fermentation _ #2_ Oiling by machine

This is a step to remove the remaining mucilage by rubbing the beans together. This step saves water, but the center groove between the beans is not clean, so after the fermentation is completed, it is necessary to use water to clean the remaining mucilage.

The oiling by machine method overcomes some of the disadvantages of natural fermentation, but it has other disadvantages: the equipment is quite expensive; consumes a lot of electricity; many beans will be peeled and the green coffee has no protective layer, so it is difficult to preserve. 

The most important thing in the washed coffee process is to make sure not to damage the outer skin and bean when the husk is removed.

There are many methods to check whether this step is complete. Some manufacturers roll the beans between two fingers. If the grain surface feels smooth, there is friction, and a squeaking sound, the process is complete. Others test by inserting a long plant into the fermenter. When the plant is upright, supported by water containing a lot of pectins, the fermentation is complete.

Step 4: Drying 


Step 4_ Drying

  • After fermentation, the coffee is washed to remove impurities from the beans. Next, the seeds are dried. Usually, sun drying is still the preferred technique because the sun’s ultraviolet rays bleach the chlorophyll in the beans, reduce the herbaceous smell in the coffee, and it costs less by spreading the seeds on a concrete drying yard or using a drying rack. At this time, the coffee needs to be layered from 2 to 10 cm and must be turned regularly with a large rake to ensure a slow and uniform drying process, avoid fermentation, mold, avoid being wet by rain or invading bacteria.
  • When there is a lack of sunlight or high humidity, some manufacturers use a dryer to dry the seeds, reducing the moisture content of the seeds to 10% – 12%. Machine-dried coffee is undervalued than sun-dried coffee, and even ground-dried coffee dries too quickly, resulting in coffee not reaching the best quality. 
  • After drying, they are now called parchment coffee and will be packaged for preservation, or processed in other refining stages.

Advantages and disadvantages of the washed coffee process

The washed coffee process has both advantages and disadvantages.


Advantages and disadvantages of the washed coffee process

Advantages of the washed coffee process

By applying the washed coffee process, a higher flavor quality has been created for the coffee. In this processing, because coffee beans must undergo fermentation by the bean’s own enzyme system or with the participation of the enzyme system of microorganisms, it helps to preserve the maximum amount of acid in the raw coffee beans, thereby ensuring the characteristic natural acidity of each type and creating a flavor that is often favored by coffee connoisseurs. For high-quality coffee varieties like Arabica, this method is the best choice. Because it helps preserve and develop the maximum flavor of the coffee. Besides, this method can also be invested on an industrial scale.

Disadvantages of the washed coffee process

  • One of the biggest disadvantages of the washed coffee process is the excessive use of water. Poor wastewater treatment can lead to environmental pollution because the wastewater after fermentation contains many toxins. 
  • The person performing the washed coffee process must be highly knowledgeable, and should closely monitor the entire fermentation process to avoid the formation of undesirable flavors due to over-fermentation. Because a few small errors will affect the taste and quality of coffee.
  • This method is also quite expensive, requires high costs, uses many machines and large amounts of water.

Markets are interested in washed coffee beans

Washed coffee beans are widely consumed around the world, but the most popular are still in Europe, America, and Japan. Especially for Europeans, Arabica coffee is an indispensable part of their lives.

FAQs about the washed coffee process

Here are some frequently asked questions about the washed coffee process.

Apart from the washed coffee process, is there any other process, and what are the biggest advantages of the washed coffee process?

Currently, in the world, there are 3 most popular ways to process coffee: washed processing, dry processing, and honey processing. Each method has certain advantages and disadvantages.

However, based on the characteristics of the three methods above, the washed coffee process is suitable for coffee growing areas with abundant water resources, especially hot and humid tropical environments like Vietnam.


K-Agriculture Factory

Is it possible to visit K-Agriculture Factory’s washed coffee process line?

Totally possible! K-Agriculture Factory’s washed coffee process line is a high-quality standard process, with modern machinery and professional workers, so buyers can be completely assured of the product quality that K-Agriculture Factory provides.

Is the price of washed coffee beans higher than other processing methods?

Because of the sophistication in processing and preservation to ensure the quality of each coffee bean, the price of washed coffee beans is always about 20-30% higher than that of dry-processed coffee beans.

How to contact K-Agriculture Factory for washed coffee beans?



Whatsapp: +84855 555 837 (Ms.Sarah)



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About author Camila Nguyen

She has 13 years experience in connecting B2B customers around the world and provide best-quality agricultural products from Vietnam to them. She would love to share her knowledge about agricultural products through the blogs. You can contact her on Whatsapp via number: +84 84 4444 867 to get the free consultancy

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