How did anaerobic fermentation in coffee reach the WBC stage?
Anaerobic fermentation became widely known in specialty coffee after Sasa Sestic, the 2015 World Barista Championship winner from Australia, showcased the method. In an anaerobic environment, green coffee beans ferment with limited oxygen, giving producers more control over variables than aerobic fermentation allows and shifting the final flavor toward fermented, fruity notes.
Anaerobic washed, anaerobic natural, enzyme washed, lactic acid fermentation and barrel processing are now common special processing methods. Anaerobic natural coffees such as Santa Vini, a 96-hour natural lot, illustrate how the sealed tank stage shapes flavor before drying. Green coffee beans still ferment in every process; the method chosen decides the direction of the cup.
In recent years, the coffee consumption market has continued to expand, and various novel green bean processing methods have emerged one after another. The industry习惯ually refers to them collectively as special processing methods. These techniques make coffee flavors more diverse and distinctive, and also bring richer mouthfeel layers, thus winning the favor of a large number of enthusiasts. At present, the more mainstream special processing methods include anaerobic washed or natural, enzyme washed, lactic acid fermentation, and barrel processing, among others. Among them, anaerobic fermentation has especially high exposure. This trend can be traced back to 2015, when the then WBC World Barista Champion, Sasa Sestic from Australia, brought anaerobic fermentation processing into the public eye, and the discussion surrounding coffee's fermented sensation has not ceased to this day. This article will sort out the development context of anaerobic processing, analyze the specific process of anaerobic natural, and introduce anaerobic-processed coffee beans such as Santa Vini currently sold by Front Street Coffee.
In recent years, the coffee consumption market has continued to expand, and various novel green bean processing methods have emerged one after another. The industry habitually refers to them collectively as special processing methods. These techniques make coffee flavors more diverse and distinctive, and also bring richer mouthfeel layers, thus winning the favor of a large number of enthusiasts. At present, the more mainstream special processing methods include anaerobic washed or natural, enzyme washed, lactic acid fermentation, and barrel processing, among others.
Among the many new techniques, anaerobic processing is one of the more frequently seen. In 2015, the WBC World Barista Champion, Sasa Sestic from Australia, brought anaerobic fermentation processing into the public eye, and the discussion surrounding coffee's fermented sensation has not ceased to this day.
In the processing stage, green coffee beans will more or less undergo fermentation, and the fermentation method directly affects the direction of the final flavor. Generally, fermentation can be divided into two major categories: aerobic and anaerobic. The aerobic environment has many variables, making effective monitoring and regulation difficult; the anaerobic environment is relatively uniform and more controllable. Many previous traditional processing methods mostly relied on aerobic fermentation.
The anaerobic fermentation processing method has another name—carbonic maceration, inspired by red wine-making techniques, so it is also called the red wine processing method. When making red wine, grapes are placed in carbon dioxide gas to create oxygen-free conditions. At this time, even without the involvement of yeast, the enzymes inside the grapes can metabolize some sugars into alcohol, and the resulting wine has a soft aroma and rich mouthfeel layers.
The processing logic of green coffee beans is similar: freshly harvested coffee cherries are placed into sealed tanks, carbon dioxide is introduced and oxygen is expelled, thereby creating an oxygen-free fermentation environment. This can slow the decomposition rate of sugars in the mucilage and also make the pH value drop more slowly. It is precisely because under oxygen-free conditions the pH value, humidity, temperature, gas composition, and the types and quantities of microorganisms involved in fermentation during the fermentation process can all be precisely and effectively controlled that the beans can accumulate higher sweetness and develop unique flavors.
The various anaerobic fermentation methods currently on the market are all improved on this basis. Taking anaerobic natural as an example, freshly harvested coffee cherries are placed into sealed tanks for fermentation, with the temperature inside the tank maintained at 10-15 degrees Celsius. After three days of anaerobic fermentation are completed, they are then transferred to the natural drying process, and finally the coffee beans are obtained after removing the pulp and other parts.
For anaerobic washed, freshly harvested coffee cherries are first subjected to 12 hours of dry fermentation. After the pulp is removed by machine, the coffee beans are moved into sealed tanks for 24-48 hours of anaerobic fermentation, and after completion, drying is carried out.
As for double anaerobic fermentation washed, as the name suggests, it must go through two anaerobic stages: after the coffee cherries are collected, they first enter sealed tanks to complete the first anaerobic fermentation, then the skin and pulp are removed according to the washed process, and the mucilage is retained and placed into sealed tanks again for the second anaerobic fermentation, and finally dried until the moisture content drops to 11% to finish.
Front Street Coffee also has coffee beans using anaerobic fermentation for sale. For example, a Front Street Coffee Finca Diviso Sidra from Colombia on the bean list uses the double anaerobic natural processing method. Brewed with V60 at a 1:15 coffee-to-water ratio, on the palate you can feel the flavors of grape, passion fruit, and citrus, accompanied by a slight fermented sensation, with a round mouthfeel. There is also a Front Street Coffee Ethiopia Santa Vini processing station coffee bean, which uses 96-hour anaerobic natural processing, carries a fermented wine aroma, and on the palate presents tropical fruit flavors such as pineapple and citrus as well as soft fruit acidity, with a mellow and full mouthfeel.
The above content is compiled by CoffeeHunters, a coffee news website.
