Carbonic Maceration
Carbonic Maceration borrows from winemaking, fermenting whole cherries in a CO₂-saturated sealed environment to produce exceptionally refined and complex flavors.
What is Carbonic Maceration?
Carbonic maceration (CM) is borrowed from Beaujolais winemaking. Whole coffee cherries are placed in a sealed vessel, which is then flushed with CO₂ to displace oxygen. Under pressurized CO₂, the cherries undergo intracellular fermentation — fermentation happening inside the fruit cells themselves.
Difference from Anaerobic Fermentation
The two are often confused, but there is a key distinction:
- Anaerobic fermentation: oxygen is removed and microorganisms (lactic acid bacteria, yeasts) drive fermentation
- Carbonic maceration: CO₂ is actively injected under pressure; fermentation is primarily intracellular, yielding more refined and controllable flavors
Processing Steps
- Rigorous sorting: only consistently ripe cherries are used
- Loading: whole cherries are placed in sealed stainless steel tanks
- CO₂ injection: food-grade CO₂ fills the vessel, removing all oxygen
- Temperature-controlled fermentation: slow fermentation at 8–18°C for 72–200 hours
- Monitoring: precise tracking of pressure, pH, and temperature
- Post-processing: after fermentation, washed or natural drying is applied
Flavor Profile
- Refined florals: jasmine, rose, and lavender
- Candied fruit: peach, white nectarine, and candied strawberry
- Cinnamon and spice: a distinctive aromatic spice character
- Creamy texture: exceptionally smooth mouthfeel
- Long, evolving finish: flavor layers unfold gradually on the palate
Competition Pedigree
CM gained worldwide attention in 2015 when Sasa Sestic won the World Barista Championship (WBC) using this method. It has been a fixture in top competitions ever since.