How does anaerobic coffee processing change the cup?
Anaerobic coffee processing means fermenting fresh cherries without oxygen, either in a stainless steel tank fitted with a one-way valve or in a sealed bag with the excess air expelled. As carbon dioxide builds up and replaces oxygen, fermentation at a certain stage produces flavors reminiscent of stone fruits and peaches, plus a dense mouthfeel and an aroma that reads as sweeter.
The technique itself is simple; the difficulty is controlling how far fermentation goes. Because early results drew attention, producing regions worldwide copied the method and processing coffee beans this way became common. Colombia is one source of examples: comparing anaerobic natural and anaerobic washed lots side by side shows how the same approach diverges in the cup.
In recent years, any coffee processing method that claims to be innovative seems unable to avoid the word "anaerobic." In fact, the principle of anaerobic processing is not complicated. Whether you put fresh cherries into a stainless steel tank with a one-way valve or seal them in a bag and expel the air, an oxygen-free environment can be achieved. The real difficulty lies in precisely controlling the degree of fermentation, not the technique itself. When oxygen is gradually replaced by carbon dioxide, fermentation at a certain stage will develop flavors reminiscent of stone fruits and peaches. This discovery quickly sparked imitation across major producing regions worldwide, and anaerobic processing became popular as a result. Beyond its signature flavors, anaerobic processing can also give coffee a dense mouthfeel and a sweeter aroma. This article will take several Colombian specialty coffees from the Front Street Coffee bean list as examples to compare in detail the taste differences between anaerobic natural and anaerobic washed.
These days, it seems coffee processing cannot be called innovative unless it involves a bit of anaerobic fermentation. Actually, anaerobic processing is not particularly high-tech. Putting fresh coffee cherries into a stainless steel tank with a one-way valve—as carbon dioxide is continuously released and oxygen is continuously replaced—counts as anaerobic; placing fresh cherries into a sealed bag and expelling excess air also counts as anaerobic.
So the hard part of anaerobic processing is not how to achieve it, but how to control and manage it. At the very beginning, because anaerobic processing reduces the involvement of oxygen, fermenting to a certain degree will definitely bring out flavors similar to stone fruits and peaches. More and more people discovered this, and gradually, major producing regions around the world rushed to imitate it. That is how anaerobic processing became popular worldwide.
This kind of anaerobic processing, besides bringing specific flavors, can actually also bring a dense mouthfeel and an aroma that makes you perceive more sweetness, so you feel the coffee is "sweeter." Back to what was just said: the core is not whether anaerobic processing is used, but that controlling the degree of anaerobic fermentation is the key.
When it comes to what flavors anaerobic coffee has, just look at several Colombian specialty anaerobic coffee beans on the Front Street Coffee bean list. You should know that Colombia has 11 different altitudes, and each altitude has unique flavors, which is unmatched by anywhere else in the world.
These Colombian coffees are: Front Street Colombia Flower Moon Night, whose processing method is anaerobic natural, with brewing flavors of strawberry jam, fermented wine aroma, and chocolate.
Front Street Colombia Rose Valley, whose processing method is anaerobic enzyme washed, with brewing flavors of rose, white peach, and liqueur chocolate.
Front Street Colombia Finca Paraiso Sakura, whose processing method is double anaerobic washed, with brewing flavors of mugwort, berries, fermented aroma, spices, and strawberry jam.
The above content is compiled by CoffeeHunters, a coffee news website.
