How It Works
In carbonic maceration, whole bunches of uncrushed grapes are placed in a sealed vat that is then filled with carbon dioxide gas. With no oxygen present, an intracellular fermentation begins inside each intact grape berry, powered by the grape's own enzymes (not yeast). This anaerobic process converts sugar to alcohol within the berry itself, extracting colour from the skins without extracting harsh tannins.
The Process Step by Step
- Whole bunches are placed in a sealed tank — no destemming or crushing
- CO₂ blanket is added (or generated by the weight of grapes crushing the bottom layer)
- Intracellular fermentation occurs inside each berry for 1–3 weeks at 25–35°C
- Free-run juice is drained — already partially fermented and deeply coloured
- Press wine is gently pressed from remaining grapes
- Final fermentation by yeast completes the conversion of sugar to alcohol
Semi-Carbonic Maceration
In practice, most Beaujolais producers use semi-carbonic maceration: whole bunches are added to the tank without added CO₂. The bottom grapes are crushed by weight and begin traditional fermentation, producing CO₂ that creates the anaerobic environment for the grapes above. This hybrid approach produces wines with more complexity than pure carbonic maceration.
Signature Flavour Profile
Carbonic maceration produces distinctive esters: isoamyl acetate (banana), ethyl cinnamate (cinnamon), and ethyl butyrate (bubblegum/strawberry). Combined with bright cherry fruit and very low tannins, these create the immediately appealing, gulpable character of Beaujolais Nouveau and similar wines.
Beyond Beaujolais
While Beaujolais is the most famous user, carbonic maceration is widely used in Rioja for young joven wines, in the Languedoc for easy-drinking reds, and increasingly by natural wine producers worldwide seeking fresh, fruit-forward expressions.