🍷 Carbon dioxide
A gas released during fermentation; in sparkling wine it stays as bubbles.
Carbon dioxide is a gas released during alcoholic fermentation. Yeast eats the sugar in the must and turns it into alcohol and carbon dioxide. That is why bubbles rise in fermenting must and it seems to "boil".
In still wine the gas escapes or remains in a small amount. In sparkling wine it is kept on purpose: the bubbles are dissolved carbon dioxide that is released when the bottle is opened. The gas is also needed for carbonic maceration, when whole bunches ferment inside the berries under a blanket of gas.
The gas has a dangerous side too. It is heavier than air and collects low down, especially in a closed cellar during fermentation. Breathing such air is dangerous, so cellars need ventilation. This is a known issue for wineries: carbon dioxide poisoning is described as one of the risks of working with fermenting wine.
How it connects to Wine
🍷 Carbon dioxide → kind of → 🍷 Alcoholic fermentation → gives → 🍷 Wine
Links
- Previous step
- 🍷 Carbonic maceration
- Next step
- 🍷 Sparkling wine
- Where it is found
- 🍷 Semi-sparkling wine, 🍷 Champagne
- What it affects
- 🍷 Carbon dioxide hazard in cellars
- Part of
- 🍷 Alcoholic fermentation
Frequently asked questions
Where does carbon dioxide in wine come from?
It forms in fermentation: yeast turns sugar into alcohol and carbon dioxide.
Why does sparkling wine need it?
The bubbles in sparkling wine are dissolved carbon dioxide.
Why is carbon dioxide dangerous in a cellar?
It is heavier than air and collects low down, so a cellar needs ventilation.
What to read next
- 🍷 Champagne — Sparkling wine with a designation of origin from Champagne: second fermentation only in the bottle, at least 15 months of ageing (vintage 36), seven permitted grapes.
- 🍷 Semi-sparkling wine — EU categories 8 and 9: 1–2.5 bar of carbon dioxide and at least 7 % actual alcohol; frizzante, Perlwein, pétillant.
- 🍷 Carbon dioxide hazard in cellars — During fermentation the gas collects low in the cellar, so ventilation is needed.