The natural process, also known as the dry process or unwashed process, is a method of processing coffee beans that involves drying the cherries with the fruit intact, allowing them to naturally ferment and dry. This process is one of the oldest and simplest methods of coffee processing and is commonly used in regions where water is scarce or expensive.
Here are the main steps involved in the natural process:
- Drying: Instead of removing the outer skin and pulp, the harvested cherries are spread out on drying beds, patios, or raised platforms to dry under the sun. The cherries are left to dry with the fruit intact, and they are regularly turned or raked to ensure even drying and prevent mold formation. The drying process can take several weeks, during which the cherries lose moisture and shrink, while the sugars and flavours intensify.
- Hulling: Once the cherries are fully dried, they become hard and brittle. The outer skin, pulp, and parchment layer are removed from the beans using a hulling machine or manually, revealing the green coffee beans.
- Sorting and grading: The green coffee beans are then sorted based on size, density, and quality. Any defective or damaged beans are removed, ensuring that only high-quality beans are retained for roasting.
The natural process is known for producing coffees with a unique and distinct flavour profile. The extended contact between the coffee beans and the fruit during drying imparts fruity and fermented flavours to the beans. Natural-processed coffees often exhibit intense sweetness, heavy body, and a wide range of flavour notes, including tropical fruits, berries, chocolate, and wine-like characteristics.
It’s worth noting that natural-processed coffees tend to have a more pronounced acidity and can be more susceptible to defects or uneven drying due to the longer drying period. However, when done correctly, the natural process can result in exceptional and sought-after coffees with rich, exotic flavours.
The natural process is commonly used in coffee-producing countries such as Ethiopia, Brazil, and Yemen, where it has become part of their coffee tradition and heritage.
Resulting Flavour Profile of Natural Process
- Fruit forward
The washed process, also known as the wet process or fully washed process, is a method of processing coffee beans that involves removing the outer skin and pulp of the coffee cherry before drying the beans. This process is commonly used for producing specialty-grade Arabica coffees.
Here are the main steps involved in the washed process:
- Depulping: The harvested cherries are processed using a machine called a depulper. The depulper removes the outer skin or exocarp of the cherry, exposing the coffee beans or seeds inside.
- Fermentation: After depulping, the coffee beans are covered in a sticky layer of mucilage, which is the fruit layer that surrounds the beans. To remove this mucilage, the beans are fermented in water tanks for a specific period of time. During fermentation, enzymes break down the mucilage, allowing it to be washed away.
- Washing: The fermented beans are thoroughly washed in clean water to remove the loosened mucilage. This process usually involves rinsing the beans multiple times until they are clean and free of any remaining residue.
- Drying: Once the beans are washed, they are spread out on drying beds, patios, or raised platforms to dry under the sun or using mechanical dryers. The beans are regularly turned or raked to ensure even drying and prevent fermentation or mold formation. This drying process can take several days to a couple of weeks, depending on the weather conditions and desired moisture content.
- Hulling and sorting: After the beans are dried, the parchment layer surrounding the beans becomes brittle. The beans are then passed through a hulling machine to remove this layer, revealing the green coffee beans.
The washed process is known for producing clean, bright, and balanced coffees. By removing the mucilage before drying, the focus is on the inherent flavours of the coffee beans themselves, allowing the characteristics of the origin and variety to shine through. The washed process is often favored for coffees that exhibit acidity, clarity, and floral or citrus flavour notes.
Resulting Flavour Profile of Washed Process
- Bright acidity
- Clarity of flavours
- Medium body
- Delicate and nuanced flavours
- Clean finish / refreshing aftertaste
The honey process is a coffee bean processing method that falls between the traditional washed and natural process. It is also known as the pulped natural process. In this method, the outer skin or pulp of the coffee cherry is removed, similar to the wet process. However, unlike the washed process, the sticky mucilage or fruit layer is not completely washed off from the coffee beans.
After the cherries are harvested, they are pulped to remove the outer skin. Then, instead of fermenting the beans in water to remove the remaining mucilage, they are dried with some or all of the mucilage still intact. The mucilage acts as a natural layer during the drying process, imparting unique flavours and characteristics to the coffee beans.
The honey process gets its name from the sticky texture and honey-like sweetness of the beans due to the presence of the mucilage. The mucilage can range in color from yellow to red, which indicates different levels of mucilage left on the beans during drying.
The drying process for honey-processed beans can vary, with some beans dried on raised beds or patios under the sun, while others may be dried using mechanical dryers. The drying time is longer compared to the wet process but shorter than the dry process.
Honey-processed coffees often have a balanced and complex flavour profile, with a medium body and pronounced sweetness. The retained mucilage can contribute fruity, floral, or caramel-like flavours, depending on the coffee variety and processing conditions.
Resulting Flavour Profile of Honey Process
- Blanaced acidity
- Medium body
- Smooth and rounded flavours
The Giling Basah process, also known as wet-hulled or semi-washed processing, is a unique coffee bean processing method primarily used in Indonesia, particularly in regions like Sumatra and Sulawesi. This method is specific to the local coffee industry in Indonesia and contributes to the distinct flavour profiles associated with Indonesian coffees.
Here are the key steps involved in the Giling Basah process:
- Depulping: The outer skin of the cherries is removed using a pulping machine or by hand, revealing the mucilage-covered coffee beans.
- Fermentation: The coffee beans, still coated in mucilage, are placed in fermentation tanks or buckets for a short period, typically around 12 to 24 hours. This fermentation helps to break down the remaining fruit layer.
- Washing: After fermentation, the mucilage is partially washed off the coffee beans using water, leaving a sticky residue.
- Wet-hulling (Giling Basah): The unique aspect of the Giling Basah process is the wet-hulling stage. The partially washed coffee beans, still containing some moisture and sticky mucilage, are dried until they reach a specific moisture content of around 30-35%. At this point, the beans are removed from the drying process, while they are still soft and malleable.
- Hulling and drying completion: The softened, semi-dried beans are then mechanically hulled to remove the parchment layer, which surrounds the coffee bean. This process is done while the beans are still relatively wet and pliable, leading to the removal of the parchment layer, exposing the green coffee bean.
- Final drying: The green coffee beans, without the parchment layer, are spread out on drying patios or raised beds for further drying until they reach the desired moisture content, typically around 11-12%. This final drying stage is crucial for stabilising the beans and preventing mold or deterioration.
The Giling Basah process is known for its unique characteristics and contributes to the flavour profile of Indonesian coffees. Coffees processed using this method often exhibit earthy, herbal, and sometimes spicy flavours. They can have lower acidity, a fuller body, and unique complexities that arise from the combination of the fermentation, partial washing, wet-hulling, and drying stages.
It’s important to note that the Giling Basah process is specific to certain coffee-growing regions in Indonesia and is not commonly used in other parts of the world.
Resulting Flavour Profile of Giling Basah
- Earthy and herbal
- Low to moderate acidity
- Full bodied
- Deep and “dark” flavours
- Spices and exotic nuances