Which term describes the natural transformation of sugar to alcohol and CO2?

The process that describes the natural transformation of sugar into alcohol and carbon dioxide is known as alcoholic fermentation. This is a crucial biochemical process primarily carried out by yeast, which converts the sugars present in grape juice during winemaking into alcohol and CO2. This transformation not only enables the production of alcoholic beverages but also influences the flavor profile and complexity of the wine.

Alcoholic fermentation typically occurs under anaerobic conditions, meaning it happens in the absence of oxygen, which is essential for yeast to effectively convert sugars. During this process, the yeast consumes the sugar and, as a result, produces ethanol (the alcohol) and carbon dioxide gas. The release of CO2 can also contribute to the effervescence in sparkling wines.

In contrast, chaptalization refers to the practice of adding sugar to grape juice to increase the alcohol content after fermentation, rather than describing the fermentation process itself. Malolactic fermentation is a secondary fermentation process that converts malic acid into lactic acid, softening the wine's acidity and adding complexity but is not the process of sugar conversion to alcohol. Aerobic fermentation involves the presence of oxygen, which is not conducive to the type of fermentation that yields alcohol from sugar in winemaking.