Carbonic Maceration

Carbonic maceration is a processing technique adapted from natural winemaking (Beaujolais Nouveau famously uses it) in which whole, intact coffee cherries are placed in a sealed tank that is then filled with CO₂ to displace all oxygen. Fermentation proceeds intracellularly inside each cherry, driven by the cherry's own enzymes rather than external yeast. The resulting cup profile is notably fruity, wine-like, and aromatic — often showing tropical fruits, berry notes, and a silky texture. The technique entered specialty coffee competition at the 2015 World Barista Championship, where Australian barista Sasa Sestic used carbonic maceration-processed Colombian coffee to win the title.

Background & Context

Carbonic maceration is a fermentation technique borrowed from natural wine production (used notably in Beaujolais) and applied to coffee processing. The method involves placing whole, intact coffee cherries into a sealed, oxygen-free (anaerobic) container, then introducing CO₂ to displace any remaining oxygen. In this environment, the cherry undergoes an intracellular fermentation process driven by enzymes within the fruit itself, before external microorganisms begin acting. The result is a fundamentally different flavour compound profile compared to traditional aerobic or standard anaerobic fermentation — typically more wine-like, intensely fruity, with unique esters and higher alcohol derivatives that produce notes of red berries, grape, tropical fruit, and malic acidity. The process was first systematically applied to coffee by Camilo Merizalde in Colombia around 2015 and gained significant attention in the specialty and competition circuit. The 2021 World Barista Champion, Diego Campos (Colombia), used a carbonic maceration Sidra variety coffee from Las Flores farm in his championship routine. CO₂ management and temperature control (typically 18–22°C for 24–72 hours) are critical — any oxygen exposure during fermentation can create off-flavours.

Practical Use

Carbonic maceration coffees are among the most polarising in specialty — their intense fruit-forward profiles delight some and overwhelm others. Start by brewing them at lower temperatures (88–91°C for filter) to prevent amplifying alcohol-adjacent notes. For espresso: extend pre-infusion and reduce temperature slightly (92–93°C). Tasting notes like 'Pinot Noir', 'blueberry jam', or 'wine grape' on the bag are reliable indicators of carbonic maceration processing. Pairing: exceptional with dark chocolate.

Related Terms

Related terms: Anaerobic fermentation — the oxygen-free environment prerequisite. Aerobic fermentation — the traditional alternative. Colombia — origin of carbonic maceration in coffee. Natural process — similar whole-cherry approach without CO₂ control.