Which processing method involves fermentation to eliminate mucilage from the beans?

The washing process, also known as the washed method, involves fermenting the coffee cherries to remove the mucilage that surrounds the beans. In this method, the cherries are first harvested and then pulped to separate the beans from the outer fruit. After this, the beans are soaked in water, allowing natural fermentation to occur. During fermentation, specific microorganisms break down the mucilage, which helps cleanse the beans and prepares them for drying. This results in a cleaner flavor profile and is particularly desirable in regions where high-quality coffee is produced.

In contrast, methods such as natural and semi-washed involve different processes in handling the mucilage and do not rely primarily on fermentation to eliminate it. Natural processing leaves the beans in the fruit longer, allowing them to dry with the mucilage intact, while semi-washed processing may involve some removal of mucilage but does not employ fermentation as the primary means of doing so. Sun-drying refers more to the drying method used after the beans have been processed, rather than the fermentation involved in mucilage removal.