Anaerobic process
What does this process involve?
It is the prolonged fermentation of coffee that occurs within the cellular structure of the cherries, which consists of the chemical reaction that occurs when water and sugars present inside the cherry are mixed, causing bacteria, yeasts and other microorganisms to break down the sugars and convert them into acids or alcohols.
Process to achieve fermentation
The whole coffee cherry is placed in a sealed, airtight container, usually a stainless steel tank, but plastic tanks or bags can also be used. The container must be filled with carbon dioxide (CO2) to eliminate oxygen. As the coffee ferments, bacteria break down the sugars into carbon dioxide and alcohol. When there is enough carbon dioxide, the pressure inside the system increases, so a valve must be installed to release the pressure without allowing oxygen to enter the chamber.
The duration of carbonic maceration ranges from a few hours to several days. Carbon dioxide prolongs fermentation by slowing the breakdown of sugars, allowing for the development of unusual flavors in the grain, without the vinegary notes typical of a long fermentation. The pH also changes slowly, resulting in lower alcohol acidity. Temperature and fermentation time play a key role. These are variables that can be controlled to achieve successful results.
It can be used for washed and natural coffee
Carbonic maceration is not a new coffee processing method, but rather a step that can be included in either the washed or natural process. In washed carbonic maceration, ripe coffee cherries are hand-picked, sorted, and pulped before being placed in a sealed tank. In natural carbonic maceration, the cherries are placed in sealed tanks and, after processing, are dried on raised African beds to achieve the appropriate moisture content.
Qualities that carbonic maceration brings to coffee
Fermentation is evolving the way coffee beans are flavored, but it is still a topic under exploration in the search for ways to enrich and highlight the aromatic attributes; however, it offers coffees with a more aromatic profile, with sweet notes and greater body.
