Alcoholic fermentation

When you want to make wine from ripe grapes, yeast is the magic word, as alcoholic fermentation can only get underway with the help of microorganisms like yeast. Yeast feeds off the sugar in grape juice, producing alcohol, carbon dioxide gas (CO2) and heat. Once the yeast has consumed all the sugar, the alcoholic fermentation ends. At this stage, the wine is «dry».

The more sugar the grapes originally contained, the higher the alcoholic content of the finished wine. Most dry wines have an alcohol content between 11.5 and 16% by volume.