Winemaking
Carbonic maceration
Fermenting whole uncrushed grapes under carbon dioxide, producing very soft tannins and distinctive aromas.
Overview
Whole bunches are placed in a sealed vessel filled with carbon dioxide. Without oxygen, the berries begin fermenting internally using their own enzymes before yeast gets involved.
The result is very low tannin extraction and a set of characteristic aromas — banana, bubblegum, kirsch — produced by the process rather than by the grape. The banana note comes from isoamyl acetate.
Semi-carbonic maceration, more common in practice, involves filling a vat with whole bunches so those at the bottom are crushed by weight and start a conventional fermentation, generating carbon dioxide that blankets the intact fruit above.
Sources
Sources consulted
- WSET educational materials and the Systematic Approach to Tasting — Wine & Spirit Education Trust
More in winemaking
Winemaking
Fermentation
Yeast converting sugar into alcohol and carbon dioxide — the step that makes wine wine.
Winemaking
How red wine is made
Fermenting grape juice in contact with the skins, which is where colour and tannin come from.
Winemaking
How white wine is made
Pressing the juice off the skins before fermentation, then fermenting the clear juice.