Coffee processing is a topic that you’ve probably heard about more than once or twice. It is just one of many elements that influence the final taste of the brew in your cup, but it undoubtedly sparks the most interest and is often dissected and analyzed. So, let’s take a closer look at it.
Contents:
Learn the Methods
What Influences the Taste?
Characteristics
What is Important When Choosing a Method?
Natural
Washed
Pros and Cons
Learn the Coffee Processing Methods
Today’s blog is presented by our coffee trainer Michał Żmuda, who will guide us through coffee processing. Behind the doors of JAVA University, Michał trains, entertains, feeds with coffee, conducts cuppings, and works with our Head Roaster Rafał on profiling our coffees. Michał knows so much about coffee that it makes your head spin, but he himself admits that he still sees how much there is left to learn. He has recently reviewed coffee processing thoroughly to help us put together this enjoyable blog read. We invite you to dive in.
Young coffee seedlings
What Influences the Taste of Coffee?
The final taste of the brew in your cup is primarily influenced by three successive phases—fruit ripening on the coffee plantation, bean processing, and coffee roasting. At each stage of working with coffee—from the plantation to the cup—the most important goal, from the perspective of those responsible for each phase, should be to bring out the full potential hidden within the bean.
What is Coffee Processing?
In layman's terms, coffee bean processing is the method of “pitting” the fruit, i.e., removing the pulp from the seed inside. Interestingly, coffee is an unusual fruit in this regard because, similar to almonds, the seed is more valuable than the pulp, which is rare. Hence, it was necessary to devise a method that efficiently and economically removes the pulp surrounding the coffee bean.
What is Important When Choosing a Method?
When processing coffee, it is essential to note that some methods are more dependent on weather conditions than others, and this is a non-negotiable issue. If a method requires a period of several or even a dozen days of uninterrupted, blazing sun for proper processing, then that is what is necessary. Any risk of rain excludes the use of that method or puts the farm at significant risk of loss. Similarly, some processing methods require much more time, equipment, investment, and natural resources, such as water, which is not always easily accessible. Considering all these factors, it is easy to conclude that choosing the right method is a crucial decision for the farmer or coffee producer.
NATURAL and WASHED - Characteristics of the Main Coffee Processing Methods
Natural processing, also known as the dry method, is the oldest coffee processing method. After picking the cherries from the coffee trees, they are spread in thin layers and dried in the sun until they reach the desired moisture level. Drying stations may vary slightly depending on the farm or region. Some use brick terraces, while others use special elevated beds (known as African beds) that allow air to flow freely around the cherries, ensuring even drying. To avoid mold, unwanted fermentation, and rot, the cherries are regularly turned during drying. Once the coffee cherries are properly dried, the skin and dried pulp are mechanically removed, and the green coffee is stored in silos to “rest” before export. Natural processing is popular in regions where water is scarce, such as Ethiopia and parts of Brazil.
This process elicits extreme opinions among baristas—some love it, others hate it. Coffee processed naturally always has a high body and pronounced sweetness. The natural method remarkably highlights fruity and floral notes in coffee, regardless of the variety and region it comes from. The sensory profile of naturally processed coffee typically includes berries, tropical fruits, and honey. You can also often find alcoholic aromas and overripe fruit notes.
Washed - The Wet Processing Method
Washed is the second most known and widely used method. The process begins by placing the coffee cherries in a water tank to clean them, remove any twigs and other impurities, and sort and discard unripe cherries. After this initial sorting, the coffee cherries go into a depulper, a machine that mechanically separates the pulp from the seed.
Once cleaned of pulp, the beans are placed in a water tank for controlled fermentation. The time required for fermentation depends on the climate and altitude of the region where the farm is located, but it usually takes about 24-72 hours. Generally, the higher the annual average temperature, the less time this process takes. If the coffee beans ferment for too long, it negatively affects the coffee’s flavor profile.
Interestingly, in some coffee-producing countries, such as Rwanda and Colombia, preliminary fermentation has recently become popular. In this process, the coffee cherries are left to ferment for 24-48 hours at the initial processing stage, i.e., after being placed in the first water tank. This step aims to enhance the fruity character of the brew.
Drying Process
After fermentation, the coffee beans are washed to remove any remaining pulp, and after this phase, they are ready for drying. Drying in the washed process is similar to natural processing, using brick terraces or African beds. To ensure even drying, as in the dry method, the beans are regularly turned. In some regions where there are no suitable weather conditions for outdoor drying, this process is carried out in mechanical dryers.
Pros and Cons
Washed processing is valued for enhancing the complexity and transparency of the brew’s flavor. It significantly contributes to a marked increase in acidity in the cup. Many farmers choose this processing method because it carries less risk of defects in the green bean and allows for more accurate prediction of the final result compared to natural processing, which is less controllable and predictable due to its greater dependence on weather conditions. However, the downside of the washed method is that it consumes large amounts of water, making it more expensive than natural processing and less environmentally friendly. The wet process is also impossible in some regions due to limited water access.
To complicate matters further, washed processing is divided into several subcategories, such as full washed, washed, and semi-washed. But we’ll discuss that in the next episode.
Stay tuned!
This article was prepared for you by Michał Żmuda, JAVA University Trainer
