Natural coffee , also known as dry-processed, is a traditional processing method that emphasizes sweetness and rich flavors. Unlike washed coffee, where the cherries are pulped before fermentation, in the natural process, the cherries are dried whole, allowing the beans to slowly ripen and absorb the sugars and flavors from the cherry skin.
This method is particularly used in Ethiopia, Brazil and Yemen, and produces coffees with a sweet and fruity profile. Fruit aromas , as well as notes of chocolate and spices , are typically observed in natural coffees.
1. The Harvest: A Delicate Selection
The quality of natural coffee begins with the harvest . The cherries must be harvested when they are perfectly ripe to ensure optimal sugar concentration. This is a crucial step, because if the cherries are not ripe enough, they can produce coffees with bitter and underdeveloped aromas. Conversely, overripe cherries can lead to over-fermentation and unpleasant flavors.
Statistic : According to a study conducted by the Specialty Coffee Association (SCA), selective hand picking reduces the likelihood of defects in the final taste profile of the coffee by 30%.
2. Drying: A Long and Careful Process
Once harvested, the coffee cherries are spread out on drying beds to slowly ripen in the sun. This method, which can last between 2 and 6 weeks, allows the cherries to develop more complex and sweeter aromas . Drying whole cherries also reduces organic waste , as the beans are kept in their husks, preventing material loss during the process.
High temperatures and regular air circulation are essential during drying. Drying too quickly can lead to unwanted chemical reactions , while drying too slowly can encourage mold and spontaneous fermentation , affecting the coffee's profile.
Statistic : A Brazilian study found that drying too quickly resulted in a 15% loss of floral aromas in coffee, while drying too slowly promoted alcoholic fermentation .
3. Natural Fermentation: An Ecological and Complex Process
During the drying process , the cherries slowly ferment, a phenomenon called lactic fermentation or spontaneous fermentation . Natural fermentation is a complex process where microorganisms on the cherry skins convert sugars into organic acids and other chemical compounds. This gives the coffee distinct aromas of ripe fruit, chocolate , and sometimes even floral or spicy notes.
Fermentation time depends on many factors: humidity, ambient temperature, and coffee variety. Spontaneous fermentation can sometimes lead to deeper, more interesting aromas, but it also carries the risk of developing unwanted lactic acid bacteria , which can affect the quality of the coffee.
Data : The fermentation time of cherries can vary between 3 to 6 weeks, depending on climatic conditions and the type of process chosen by the producers.
4. Harvesting and Hulling: Preparing for Market
Once the cherries have dried and the mucilage (the sugary layer) is firmly attached to the beans , they are hulled . This involves removing the outer skin of the cherries to extract the coffee beans. Once hulled, the beans are sorted and screened to remove any defects.
This process ensures that each bean is ready to be roasted, ensuring consistent quality and minimizing defects, such as organic waste that could affect taste.
Variations of the Natural Coffee Process
The natural coffee process may vary slightly depending on producer practices and local conditions. For example:
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Anaerobic fermentation process : By using airtight tanks, this process blocks access to oxygen and allows anaerobic fermentation , which develops more intense and complex aromas. This influences the development of lactic acid bacteria and carbon dioxide , producing more unique profiles.
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Eco-friendly Process : Producers are increasingly adopting environmentally friendly practices, such as reducing the water used when washing beans or using organic methods for pest control, to reduce the ecological footprint of natural coffee .
Conclusion
Natural coffee is a fascinating product that results from a long and delicate process, where each step influences the final taste. From picking to spontaneous fermentation , including drying and hulling , each phase is crucial to guarantee an exceptional coffee with sweet and fruity aromas. This traditional process highlights the richness and complexity of natural chemical reactions , creating coffees of incomparable quality.
