Charmat method or Cuve close

Charmat method or Cuve close – Method of production for sparkling wine.
Second fermentation on the tank.

The second fermentation produces a lot of carbon dioxide, CO2, which is held in a tank. Because the carbon dioxide has no way of escaping it mixes with the wine.
The colder the tank, the longer the process takes: differing from 10 to 90 days.
The longer it takes, the better the integration of the carbon dioxide in the wine.