Process: Anaerobic - Natural
Tracon Coffee, has been experimenting with new processing methods as a way to increase value and stand out among a growing number of specialty washing stations in Ethiopia. Tracon has been trialing anaerobic fermentation with several of their washing stations in Yirgacheffe since 2015 and have been producing Anaerobic Natural coffees at Biloya washing station since 2018.
Farmers selectively handpick ripe cherry and deliver it to Biloya. At intake, employees visually inspect cherry and accept only fully ripe cherry for anaerobic fermentation. Selected cherry is tightly packed in GrainPro bags and sealed shut. Cherry ferments anaerobically (without oxygen) for 18 to 24 hours.
After fermentation, cherry is carefully removed from bags and laid to dry in direct sunlight on raised beds. Workers turn cherry frequently to promote even drying. It takes approximately 2 to 3 weeks for cherry to dry.
As more producers and washing stations enter specialty coffee, unique processing methods are a new way to stand out among the increasing number of sellers. One of those newer processing methods is anaerobic fermentation.
Anaerobic fermentation occurs in sealed containers. The seal means the microbes fueling fermentation quickly consume all the oxygen in the container. At that point, the environment become anaerobic (without oxygen). In this new environment, the microbes that typically breath oxygen have a harder time surviving and those that flourish on carbon dioxide (the typical byproduct of oxygen-breathing microbes) are able dominate fermentation.
Microbes are immensely diverse and have the potential to produce a wide array of flavors in coffees. Aerobic (oxygen-breathing) microbes produce different flavor outcomes than anaerobic ones, so we have the potential to produce vastly different flavors simply by changing the available resources for microbes.