Fermentation in coffee is a natural process where microorganisms (like bacteria and yeast) break down the mucilage—the sticky, sugary layer surrounding the coffee beans after the fruit skin has been removed. This process typically happens after pulping the coffee cherries and before drying the beans.
Harvesting
Ripe coffee cherries are carefully picked.
Pulping
The skin is removed, leaving the beans covered in mucilage.
Fermentation
Beans are placed in fermentation tanks (usually with or without water) for 12 to 72 hours, depending on the process. Natural enzymes and microbes break down the sticky mucilage.
End of Fermentation
The beans are washed to remove the broken-down mucilage (in washed coffee) or dried directly with the mucilage on (in honey or natural processes).
Drying
Beans are dried under the sun or in mechanical dryers.