May 17


Learn The Washed Processing Method For Robusta Beans

By Hanson Cheng

May 17, 2023

Washed processing method for Robusta coffee beans involves a significant part of the coffee-making process that contributes to the unique taste and quality of Robusta coffee. This method is known for its exceptional attention to detail, which ultimately produces a clean and bright cup with a full-bodied taste. Washed processing method is a coffee production method that separates coffee fruit from the beans and clean the beans before drying them. This article will delve into the robust coffee beans washed processing method, its unique features, and why it is the preferred choice for producing the finest Robusta coffee beans.

Overview Of The Method

The washed processing method for Robusta coffee beans is a popular method used to remove the outer layers of the coffee cherry fruit before the beans are dried. This process involves soaking the harvested coffee cherries in water and then using machinery to remove the pulp from the coffee beans.

The beans are then left to ferment in water, which helps to remove any other remaining debris or pulp. This method results in a clean and consistent flavor profile that has a balanced acidity and body. The washed processing method also allows for a greater control of the fermentation process, resulting in coffee beans that have a higher cupping score.

However, this process can be more expensive due to the amount of water used and the need for specialized machinery. Additionally, if the fermentation process is mismanaged, it can result in defects in the final product. Despite these disadvantages, the washed processing method has become a popular choice for Robusta coffee farmers and Roasters worldwide due to the high quality of the final product it produces.

Advantages of The Method

The washed processing method for Robusta coffee beans offers several advantages that make it a preferred processing method for many coffee farmers and manufacturers. One of the primary advantages of this processing method is the high-quality coffee it produces. The washing removes all traces of the cherry’s mucilage, leading to a clean and bright flavor that is desirable among coffee consumers. Additionally, the washed beans have a longer shelf life and are less prone to defects compared to other processing methods.

Another significant advantage of the washed processing method for Robusta coffee beans is that it allows for consistency in the final product. The washing process removes all unwanted particles and impurities, resulting in a more uniform and predictable batch. This makes it easier for manufacturers to provide consistent product quality and meet the demand of their customers.

Furthermore, the washed processing method is known for producing a more balanced and complex profile. The coffee beans have a better balance of acidity, sweetness, and bitterness. Moreover, it allows for more distinctive flavor notes to be achieved, making it ideal for specialty coffee drinks such as espressos, lattes, and cappuccinos.

In addition, the washed processing method has a lower environmental impact compared to other processing methods. The minimal use of water minimizes pollution of local water sources and reduces water usage in the coffee production process. Furthermore, the washing process produces less waste, reducing the amount of organic material that is discarded and ultimately reduces the environmental impact of the coffee production process.

The washed processing method for Robusta coffee beans offers several advantages, including high-quality coffee, consistency in the final product, a more balanced and complex profile, and a lower environmental impact. These benefits make it a preferred processing method for many coffee manufacturers and are essential for coffee consumers looking for a unique and high-quality coffee experience.

Disadvantages of  Process

Despite its many advantages, the washed processing method for Robusta coffee beans is not without its drawbacks. One major disadvantage is the significant amounts of water required for the process, which can strain local water resources and lead to environmental harm if not properly managed.

Additionally, the method can be time-consuming and expensive, requiring specialized equipment and skilled laborers to carry out effectively. Another potential issue is that the process can introduce unwanted flavors and aromas into the final product if not executed with precision. Finally, some argue that the washed method can result in a less complex, less nuanced coffee flavor profile compared to other processing methods.

However, despite these drawbacks, the washed processing method remains a popular choice among coffee growers and roasters for its ability to produce high-quality, clean-tasting coffee with consistent flavors and characteristics.

The Processing Of Robusta Beans

Harvesting Process

The harvesting process for Robusta coffee beans is a crucial step in producing high-quality coffee. It typically takes place between November and January, and the timing is critical to ensure that the beans are fully ripe when harvested. The process is usually done by handpicking the coffee cherries from the tree.

The cherries need to be carefully selected and picked in small batches to ensure consistency in quality. The use of machinery is discouraged in harvesting Robusta coffee beans as this may result in the picking of unripe or overripe cherries and the consequent reduction in quality.

After the cherries are handpicked, they are sorted to remove any damaged or unusable coffee fruits. This sorting process is necessary to ensure consistency in quality and to obtain the best yield. The harvested coffee is typically delivered to the processing facility within 24 hours of harvesting to prevent spoilage and ensure freshness.

Harvesting Robusta coffee beans is a labor-intensive process that requires careful attention to detail to ensure high quality and consistency. The timing of the harvest, the method of picking, and the sorting process are crucial steps that need to be done correctly to produce high-quality coffee.

Depulping Process

The depulping process is a crucial step in the production of high-quality Robusta coffee beans. It involves removing the outer skin or pulp from the beans, which is done immediately after harvesting. This process is done using a depulping machine, which separates the coffee cherries and their pulp. Once depulped, the beans are separated into two categories depending on their weight, with the heavier ones being of better quality.

The beans are then placed in a water tank, where any remaining pulp is removed through agitation, and the beans are washed thoroughly. This leaves the beans clean and free from any residual pulp or foreign matter, ensuring that they are of the highest quality possible. The depulping process is necessary to remove the outer skin of the coffee cherry and the pulp, which can negatively affect the quality of the final product if not removed correctly.

The depulping machine separates the beans from the pulp, and this is followed by thorough washing to remove any remaining pulp residue. The resulting beans are then categorized based on their weight, with the heavier beans being of better quality. The depulping process is a vital step in the production process, as it ensures the beans are clean, free from contaminants, and of the highest quality possible.

Fermentation Process

During the fermentation stage, Robusta coffee beans go through a process where naturally occurring enzymes break down the remaining mucilage after depulping. Fermentation time can range from 12 to 24 hours, depending on various factors such as ambient temperature, humidity, altitude, and bean density.

This process creates a unique flavor profile for the coffee, as the breakdown of the mucilage allows the coffee’s natural sugars and acids to develop. The fermentation tanks are essential in this stage as they provide the optimal environment to control temperature, oxygen, and ph levels which aid in the breakdown process.

After the fermentation process, the coffee is washed and ready for drying. Failure to control the fermentation process can lead to over-fermentation resulting in undesirable flavors like sourness, hard liquorice, or rotten fruit. On the other hand, under-fermentation can result in high acidity and a lack of complexity in flavor. Thus, skilled coffee farmers must closely monitor the fermentation process to achieve the desired flavor characteristics of the beans.

Washing Process

The washing process is a crucial step in producing high-quality Robusta coffee beans. After depulping, the beans are covered in mucilage that needs to be removed to prevent fermentation. This process involves soaking the beans in water and scrubbing them to remove the mucilage. The beans must be washed thoroughly to ensure that no residue remains, as any leftover mucilage can negatively affect the taste of the coffee.

The washing process typically takes between 12 and 36 hours, depending on the desired level of acidity. Some farmers opt for a longer washing time, resulting in a milder flavor profile. Conversely, a shorter washing period produces a more acidic and fruity flavor. Washing can be done either by hand or using machines. Many farmers prefer to wash by hand to ensure quality control, but machine washing is becoming more common due to its efficiency.

Farmers must also pay attention to the water used in the washing process, as any impurities can alter the taste of the coffee. In some regions, water scarcity can be an issue, and farmers may have to use recycled or rainwater. Overall, the washing step is essential for producing high-quality Robusta coffee beans with a consistent flavor profile.

Drying Process

After being washed, the Robusta coffee beans are ready for the drying process. Drying is critical in the production of high-quality coffee beans, as it ensures that the moisture content of the beans is reduced to the appropriate level. The beans are typically spread out on drying beds or patios, where they are exposed to the sun.

The drying process can take up to two weeks, during which time the beans must be turned regularly to ensure even drying. In cases where weather conditions do not permit sun-drying, mechanical dryers may be used instead. However, this method is not as popular since it can negatively affect the cup profile of the coffee. The ideal moisture content for Robusta beans after drying is between 10–12%.

Quality Control

Sorting Beans

The sorting process for Robusta coffee beans is a crucial step that is responsible for ensuring the quality of the beans. After the beans are harvested, they are first washed to remove any dirt and debris. Once cleaned, the coffee beans are sorted by size, weight, and color. This step is necessary because Robusta coffee beans are known to have more defects than Arabica beans. The sorting process is executed in a few ways, the first being hand sorting, which is the most common method for small-scale farms.

Hand sorting allows farmers to detect any defects immediately and remove them. Manual sorting is a meticulous process that requires attention to detail as the beans are sifted, and any odd beans are picked out. Additionally, hand sorting provides many employment opportunities for farmers or their families. The alternative to hand sorting is the use of machines. Machine sorting uses optical and electrical technology that has a faster process time and is more objectively accurate than hand sorting. This method is common for large-scale industrial coffee production industries.

The sorting process ensures that only high-quality coffee beans are moved onto the roasting phase. The high-quality beans have the right size, weight, and color, and they ensure the coffee’s consistency and flavor. Sorting also benefits the quality control process by creating a more uniform product. Furthermore, sorting helps in the equitable payment of coffee farmers, where beans that pass the sorting process command better prices in the market.

Grading and cupping effectively explain the quality of coffee, but the successful ranking of coffee can only occur if the beans are sorted correctly. Comprehensive sorting ensures that only high qualities are moved to the next stages of the production process. It’s important to note that defects can occur at any stage of coffee processing, making sorting a necessary step.

Beans Grading

The grading process for Robusta coffee beans plays a crucial role in determining the quality and value of the beans. This process involves a thorough evaluation of the beans based on several attributes such as size, shape, color, and defects. The grading process also aims to ensure consistency in the quality of the beans, which is essential for customers and producers alike.

To begin the grading process, the beans are sorted based on their physical characteristics such as size and density. The grading process involves categorizing the beans into various grades, each representing a distinct level of quality. For example, the highest grade of Robusta coffee beans will feature smooth texture, uniformity, and a pleasant aroma, while the lowest-grade beans will have more defects and a less desirable taste.

It is worth noting that grading’s accuracy is vital to ensure the highest quality beans. For this reason, the grading process is usually carried out by experienced professionals who have an eye for detail. Additionally, some Robusta coffee beans may not fit into any particular grade, and these beans may be classified as “off-grade” or “ungraded.” These beans usually have a lower value than graded beans due to their variability in quality.

The grading process is not only crucial for determining the quality of Robusta coffee beans but also impacts the price. The higher the quality of the beans, the more valuable they are. This pricing scheme incentivizes farmers to produce high-quality beans and encourages buyers to seek out the best quality beans. It is also important to note that some regions may have their grading systems depending on factors such as altitude and soil type.

The grading process is a crucial step in the production and trade of Robusta coffee beans. It ensures consistency in quality, incentivizes farmers to produce high-quality beans, and helps buyers to identify the best beans. In doing so, the grading process helps to ensure that consumers can enjoy the best possible cup of coffee.

Cupping Process

The cupping process is an essential step in evaluating the quality of Robusta coffee beans that have undergone the washed processing method. Cupping is a sensory evaluation method that involves a group of professionals that taste the coffee and evaluate various attributes such as body, acidity, sweetness, and aftertaste.

During the cupping process, the professionals use a specific form that allows them to score the coffee based on its aroma, flavor, and other aspects. This grading system allows professionals to accurately and consistently score and rate the coffee, enabling coffee producers to determine the best processing methods and optimize quality.

Cupping is an essential step in the evaluation process as it allows coffee producers to obtain feedback on the quality of their products, improving and fine-tuning their processing methods.


The washed processing method for Robusta coffee beans has been shown to produce high-quality coffee with distinct characteristics. Through the use of water, this method removes any unwanted flavors or residues while highlighting the unique attributes of the coffee. It is a labor-intensive process that requires careful attention to detail, but the results can be worth the effort.

This method is particularly important for Robusta beans, which are known for their intense flavors and high acidity. By carefully controlling the water temperature and time, producers can create a coffee with a balanced acidity, full body, and pleasant aftertaste. However, there is still much research to be done on this method. Areas that need further exploration include the effect of the washing process on the environment and the potential for the use of new technologies.

Furthermore, research should focus on developing more efficient and cost-effective ways to implement the method. Despite these challenges, the washed processing method holds great promise for the future of Robusta coffee production. It has already proven to be a valuable tool in creating unique and delicious coffee, and with continued research and innovation, it is likely to become even more important in the years to come.

Future Research

There are several areas that need further research on the washed processing method for Robusta coffee beans. First, the impact of different water sources on the coffee flavor should be explored. Second, the effect of varying fermentation times on the beans’ overall quality should be investigated. Third, the use of pre-soaking before the actual washing process should be studied to optimize the method.

Fourth, the role of different drying techniques in maintaining the beans’ flavor and aroma should be looked into. Fifth, the influence of specific genetic varieties on the washed process method should be explored. Sixth, the measurement of the economic impact of using the washed processing method should be studied to determine the profitability of this technique.

These areas would significantly contribute to the development of the coffee industry as the demand for high-quality coffee continues to increase. Finding ways to enhance the processing method of Robusta coffee beans can help meet the market’s desire for excellent coffee and increase farmers’ income at the same time.

Washed Processing Method for Robusta Coffee Beans – FAQs

Q: What is washed processing method for Robusta coffee beans?

A: Washed processing method is a coffee preparation technique that involves removing the outer layers of the coffee cherry and separating the coffee bean from the pulp before being washed thoroughly by water to remove the mucilage layer.

Q: How does washed processing method affect the taste of Robusta coffee beans?

A: Washed processing method creates a clean and crisp taste profile for Robusta coffee beans. The resulting brew has high acidity and brightness, complemented by a fruity or floral aroma, and a smooth finish.

Q: What are the steps involved in washed processing method for Robusta coffee beans?

A: The steps involved in washed processing methods include picking the ripe coffee cherries, depulping them, fermenting, washing, and drying the beans. Afterward, the beans are hulled, polished, and graded before being packed for shipment.

Q: What is the advantage of using washed processing method for Robusta coffee beans?

A: The advantage of using washed processing method for Robusta coffee beans is that it removes any unwanted flavors that may arise from the pulp, producing a consistent cup in terms of flavor and aroma.

Q: How long does it take to dry Robusta coffee beans using washed processing method?

A: Drying Robusta coffee beans using washed processing method depends on various factors such as the weather, humidity, and the thickness of the mucilage layer. In average weather conditions, it takes up to two weeks or more to dry the beans thoroughly.

Q: Can the washed processing method be applied to other coffee varieties?

A: Yes, washed processing method can be applied to other coffee varieties such as Arabica, Liberica, and Excelsa. The technique is widely used in the coffee industry as it produces a consistent and clean taste profile.

Hanson Cheng

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