Carbonic maceration
also: CM process
A wine-borrowed method fermenting whole cherries under CO2 for bold, fruit-forward, distinctive cups.
Carbonic maceration is a fermentation technique borrowed from winemaking, where whole cherries are sealed in a tank that is then flushed and filled with carbon dioxide. In that oxygen-free, CO2-rich environment, fermentation begins inside the intact fruit before any depulping, which gives the method its signature character.
Why it matters: it is a specific, controlled form of anaerobic fermentation. Keeping the cherry whole under pressurized CO2 changes how flavor compounds develop, and producers tune temperature and time to steer the result. Because it is labor- and equipment-intensive, it usually appears on premium experimental lots.
In the cup, carbonic maceration coffees tend to be vivid and fruit-forward, with pronounced sweetness, winey and berry notes, and a smooth body. Like other anaerobic styles, they can be polarizing: striking to some, too far from the origin’s natural profile for others. Compare with classic washed and natural coffees, and see anaerobic-carbonic for the full treatment.