Natural or sun-dried processing is a method of coffee processing in which the beans are left to dry with the pulp intact. It is often used in regions with hot, dry climates.
What is natural processing?
The process involves placing the coffee beans on a flat surface so that they are exposed to the sun and wind to dry. The coffee beans are allowed to slowly dry while the pulp begins to ferment. This fermentation process can influence the taste of the coffee and add sour, sweet and umami fruit notes to the finish of the coffee.
How the process works
The natural processing process begins at the moment of coffee bean harvesting. Coffee fruits are manually collected and then sorted to ensure optimal quality. The beans are then spread out on large drying beds or flat surfaces, where they are exposed to sunlight. This process can take anywhere from a few days to several weeks, depending on the climate and other local conditions.
As the coffee beans dry, the fruit pulp also dries, creating a natural barrier that protects the beans from external factors. During this time, natural enzymes begin to break down the fruit pulp, adding to the complexity and final aroma of the coffee. Once the beans are fully dried, they undergo a cleaning process to remove the dried pulp and other impurities, then are sorted and packaged for shipment to coffee roasters.
How it affects the taste
Coffee processed by the sun-dried method is often characterized by an intense and robust taste, with fruit accents and hints of caramel or chocolate. Due to the natural fermentation process, the coffee can also have complex notes of flowers and spices, along with a natural sweetness and a rich body.
Advantages and risks
Despite these attractive taste characteristics, natural processing can be difficult to control and may be exposed to microbial or insect contamination. Therefore, it is often considered a less reliable method than other processing methods, such as washed processing.
Natural vs washed
Unlike washed processing, where the mucilage is removed by washing before drying, natural processing keeps the fruit pulp on the bean throughout drying — this is the main reason natural coffee has a sweeter, fruitier flavor profile, but also a less predictable result from one lot to another.
Conclusion
Natural processing remains one of the oldest coffee processing methods, valued for its intense, fruity aromas, but also for the quality-control challenges it presents during drying.