Anaerobic fermentation is when coffee beans are sealed in an airtight container, and all the oxygen is pumped out. From there, the beans are left to ferment.
Fermenting coffee beans is no new tactic. But fermenting in an oxygen-deprived zone allows for specific acids to be introduced to the coffee.
This will result in a distinct flavor profile from typical coffee types.
We have researched and written dozens of coffee-related articles. Our goal is always to deliver the best and most accurate information.
This article will cover the exact anaerobic fermentation process and how it changes the flavor profile. And other information about this delicious and unique way of making coffee.
The Anaerobic Fermentation Process
Anaerobic fermentation is often done with Columbian coffee beans. To start, we’ll give you a detailed description of what goes into anaerobic fermentation.
The first step of this process is gathering the coffee cherries. The coffee bean is the tiny hard seed inside these cherries.
Depending on the processing type, the cherry pulp is sometimes washed off, while much of the pulp and juice is left on the remaining beans.
In the case of anaerobic fermentation, you usually use a process called carbonic maceration. The fresh coffee cherries are broken down into a tank that lacks oxygen during this process.
After the maceration process, the cherries are left to ferment.
Fermentation happens when microbes grow and feed on the sugars left behind from the cherry pulp. This is why cherry pulp is essential to developing the bean flavor.
Even if the pulp will be washed away before the final roasting and distribution of the coffee beans.
Allowing the cherries to ferment without oxygen enables the microbes to create acids that otherwise would be difficult to find during fermentation.
That changes the resulting flavor of the coffee beans. Lactic acid is one of the primary acids in an anaerobic fermentation process.
After fermentation, the cherries and beans are removed from the tank and spread out on beds to dry. The flavor changes during drying as the cherry mucilage is left to dry around the beans, infusing the flavors.
Once the beans are dehydrated, any leftover dry pulp is removed. Then the coffee beans are sent off to be roasted and later turned into delicious coffee.
What Does Anaerobically Fermented Coffee Taste Like?
How does the flavor of regular coffee differ from a coffee made by this method? Coffee alone is known for its rich and earthy taste and aromatics that can fill a room.
Anaerobic coffee is very similar. It still tastes like coffee, but it will be unlike any coffee you have ever had.
The difference is an elevation in the flavor profile. Anaerobic coffee tastes creamier than regular coffee, even without adding cream or sugar.
This is due to the lactic acid created during the fermentation process.
Anaerobic coffee also tastes less bitter generally. That fermentation removes some bitterness that can come with regular coffee. This process creates something genuinely smooth and creamy.
History of Anaerobic Fermentation Coffee
Fermenting coffee is by no means new. But including an anaerobic environment, is still considered an experimental practice.
Coffee is an ancient art, and many cultivators are passionate about the tradition of their craft and may be cautious about deviating.
This anaerobic technique was mainly a coffee insider secret for a long time for those who knew where to look for it.
Anaerobic fermentation took the spotlight during the World Barista Championship in 2019.
Since then, there has been an increased interest in this technique to ferment coffee beans, and more cultivators have been giving it a try.
During the World Barista Championship, a competing barista named Jooyeon Jeon of South Korea became the champion.
She was the champion thanks to her drink of anaerobically fermented coffee and freeze-distilled milk. The glass was awe-inspiring and lifted the spirits of the judges.
That happened due to her excellent technique and the effortless ease with which she served it.
Examples of Anaerobic Fermentation Coffee
This next section will give a few examples of our favorite anaerobic fermentation coffees.
This is by no means an exhaustive list, and we encourage any reader to get out there and explore this area of coffee making further if they find they enjoy one or two of the coffees listed here.
Paradise Roasters Ethiopia Guji Wush Wush: Starting with something not Colombian, this Wush Wush variety of coffee is made with anaerobic processing. The resulting brew is floral and silky with a savory edge.
Corvus Coffee Roasters La Estella Carbonic Geisha Reserve: This is a geisha-style coffee with more great floral notes. They use a carbonic anaerobic fermentation, which adds CO2 to the macerating process. The result is a coffee that is floral, lush, and complex.
Fumi Coffee Peru Yanesha Geisha Double – Anaerobic: Continuing with the experimentation in this space, this coffee grower opted to use two stages of anaerobic fermentation to develop further the intriguing flavors that come with this technique.
This Geisha style of coffee has a very complex flavor profile, though the double processing makes the lactic acid resonate through the entire blend rather than acting simply as a leading role.
We hope that you learned plenty about the process of anaerobic fermentation when it comes to making coffee.
The process creates a distinctly flavored coffee that is creamy and light despite the lack of other additions such as milk or sugar.
As coffee growers continue experimenting with this type of fermentation, we expect to see more great things from this space that will push the world of coffee further into the future.
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