Second fermentation
The second fermentation is the process that begins after the alcoholic fermentation. This method is mandatory for red wines, but not necessary for white wines. During the second fermentation, malic acid is attacked by lactic acid bacteria so that it is transformed into milder lactic acid. The bacteria used are either already in the winery or are added artificially. This process lowers the overall acidity and makes the wine fuller and smoother. In addition, the second fermentation gives the wine a longer shelf life. However, white wines gain their freshness and effervescence especially from malic acid, which is why this process is only performed on certain white wines.