A wine without carbon dioxide, once opened, will not form any bubble as it happens in semi-sparkling wine or, even more, in a sparkling wine.

This fact is due to a precise choice: during the fermentation phase, when the carbon dioxide is produced in large quantities as a product of the sugar transformation into alcohol, it is conveyed outside the wine container, avoiding that it can dissolve in this one.

All categories of wine can be still: white, rosé and red. Usually the absence of bubbles highlights the characteristics of softness, such as sweetness (if present) and warmness (i.e. the alcohol content).