Refermentation in Bottle

Residual yeast and sugar in an improperly stabilized wine reactivate after bottling, producing CO2. Common in wines with residual sugar that were not sterile-filtered. Can also occur from malic acid in wines that didn't complete malolactic fermentation.

Unexpected slight fizz or spritz in still wine. Turbidity or cloudiness. In extreme cases, the cork may push out. Can be mistaken for intentional pétillance. The wine may taste yeasty or slightly off if the refermentation was uncontrolled.

Sterile filtration (0.45 microns) before bottling removes all yeast. Ensuring complete fermentation of all sugars. Adequate SO2 levels inhibit yeast activity. Completing malolactic fermentation before bottling.