How is semi-sparkling wine produced?

Sparkling wines are carbonated wines, whereby the pressure must be between 1 and 2.5 bar. A distinction is made between exogenous and endogenous carbon dioxide.

Exogenous carbonic acid (more precisely: the gas carbon dioxide, which then dissolves in the liquid in the form of carbonic acid) is added to the still wine after it has been completed in a pressurised tank(impregnation process). In this case, the gas does not originate from wine production, but is usually technically produced. The end product must then be labelled as "sparkling wine with added carbon dioxide".

Endogenous carbon dioxide, on the other hand, comes from wine production (because during fermentation, the yeast converts the sugar in the grapes into alcohol and carbon dioxide ). It is either also (re-)added to the finished still wine in the pressurised tank or is produced during a second fermentation of the base wine, in which the carbon dioxide formed cannot escape and therefore dissolves in the wine.

Wines with a carbon dioxide pressure of 3 to 6 bar are called sparkling wines.