Coffee Processing Methods
First and foremost, it's worth understanding that coffee is a berry. Before you get coffee in its roasted form, the coffee berry needs to be processed, and how to process it is decided by the farmer. It all depends on their preferences, capabilities, and weather conditions.
Natural Processing of Green
Dry or natural processing is a traditional method of coffee processing, and it is much cheaper than the washed method. Moreover, I believe it is quite environmentally friendly.
After harvesting, the coffee cherries are spread out on beds, concrete platforms, or just on some mat in front of the house. The key is to expose the coffee to a flat surface under the scorching sun. The drying process typically takes 3-4 weeks.
After a few weeks, it becomes possible to peel the cherry and extract the beans from it. During the drying process, the cherries are periodically turned to ensure that all beans are evenly dried from all sides. If drying is uneven or prolonged, it can adversely affect the taste of the resulting beverage. They may acquire a woody or even a rotten taste. Agree that no one would want to drink such a cup, let alone pay for it.
After drying, the outer skin and dried pulp are removed from the cherry. Then the beans, ideally, are sorted by size using a special sieve and packaged in bags. Sorting in this method is not always performed, but again, it depends on the farm. Moreover, some farmers also use special sieves to separate parchment from the general harvest.
Natural processing is characterized by:
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A rich and vibrant flavor
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More sweetness in taste
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A dense body of the beverage, especially noticeable in espresso and moka
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Pronounced berry and fruity undertones in the taste
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Cost-effectiveness compared to washed or honey processing, as it doesn't require extensive water resources
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Some Arabica varieties retain their characteristics better after natural processing
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Washed processing leads to the loss of some minerals and substances, affecting the taste of the final beverage. It's neither worse nor better, but it's important to recognize it as a distinct processing method with its own impact on the coffee's flavor.
How to distinguish natural processing from washed processing? Coffee beans that have undergone natural processing have a uniformly dark pattern in the center of the bean. The final layer that remains is the silver skin, which is removed during the roasting process. In the natural processing method, sugar permeates all layers of the bean and even penetrates the silver skin, causing it to darken during roasting. In washed processing, this vein remains light.
Natural processing does have its drawbacks:
People who harvest coffee on farms mostly get paid by the weight of the collected raw material. The control over the ripeness of the harvest is lower than in the case of washed processing, leading to more occurrences of green berries and resulting in an uneven crop.
The harvest is rarely subjected to additional control and is often not sorted.
Green beans are much lighter than ripe ones. Even when taking a handful of roasted coffee from a bag, you may find green beans that are significantly lighter than the rest. This contrast is particularly noticeable in espresso roasts. Green berries contain less flavor and sugars, affecting the roasting process. Without sugars, there is nothing to caramelize, resulting in light-colored beans.
Below is an example of drying beds/areas for coffee. I do not know the author of the photo. All rights to the photo belong to them.
Washed processing of green coffee
Washed processing of green coffee, also known as wet or moist processing, involves the use of water. This method can be costly in regions facing water supply issues, and it has some environmental drawbacks. In areas with high air humidity, natural processing may be impractical or present challenges, leading farmers in such regions to remove the pulp from the berries immediately after harvesting for washed processing.
In washed processing, all substances and sugars transferred during the dry method are immediately lost. However, the beans retain a layer of sticky proteinaceous material that does not dissolve in water. Washed processing is more complex than dry processing, involving several stages, including sorting the coffee berries by ripeness. This method has numerous nuances that are worth exploring in more detail.
During the sorting process in water, there is a notable feature. Ripe berries are harvested, and the sorting process occurs again. The ripest berries float to the top and go into the first grade. These berries are considered the best, and coffee made from this raw material is more expensive. These beans are often used in elite or premium blends. Subsequently, other berries gradually float down and are categorized into the second, third grade, and so on. As the grade decreases, the quality of the beans and the price of coffee from these beans also decrease.
Washed Coffee Characteristics:
Washed coffee exhibits fewer sweet notes in its flavor profile and has a less intense taste, but it is cleaner and more understandable. This is attributed to human presence at every stage of grain processing, leading to better overall control compared to the dry processing method. The berries are more uniform in ripeness and size.
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Reduced sweetness: The taste is less sweet compared to other processing methods, providing a cleaner and more understandable flavor. This is because human intervention is present at every stage of grain processing, and production is better controlled than with the dry processing method. The berries are more uniform in ripeness and size.
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Increased acidity: Washed coffee exhibits higher acidity in taste due to prolonged contact with water.
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Enzymatic properties and terroir expression: Washed processing emphasizes the enzymatic properties of grains and the expression of terroir, contributing to a more pronounced flavor.
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Higher cost: Washed coffee production has higher costs compared to other methods. This is due to the complex processing, a large volume of fresh water used, and a greater number of people involved in the processing. As a result, the price of washed coffee is usually higher.
Enzymatic properties are inherent characteristics bestowed by nature. Soil, climate, pressure, altitude, water – all these factors influence the final flavor profile of coffee grown in a specific place or region.
Honey Coffee (Semi-washed processing)
The Honey processing method, still referred to in the professional community as Hani. No choice :) This method is generally considered one of the types or methods of wet processing, although in fact, it is a semi-washed process that combines the best of natural and washed processing. The golden mean, quite literally. During drying, the coffee takes on a golden, honey-like hue, hence the name of the processing – Honey. During this process, only part of the pulp is removed from the beans, leaving the mucilage. The beans are then spread out on a flat surface under the sun, as described in natural processing. Subsequently, the remaining layer is removed using washed processing techniques. This method results in high-quality clean beans with all the advantages of washed processing, while preserving some characteristics of dry/natural processing, where sugars are transferred from the pulp to the beans.
Characteristics of Honey-Processed Coffee:
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When prepared correctly, this coffee is distinguished by its smoothness. While not considered a characteristic for evaluating coffee in professional circles, for regular coffee enthusiasts, it can be an interesting descriptor.
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The coffee itself is more uniform.
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As it falls between the washed and natural processing methods, the intensity of the brew is balanced. I weigh, I'm all for a balanced taste.
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Acidity is more pronounced than in the natural processing method but milder than in the washed processing method.
