Sugars in wine The technique allows for a better extraction of wine polysaccharides. Sugars in wine Sugars in wine are at the heart of what makes winemaking possible. During the process of fermentation, sugars from wine grapes are broken down and converted by yeast into alcohol (ethanol) and carbon dioxide. Grapes accumulate sugars as they grow on the grapevine through the translocation of sucrose molecules that are produced by photosynthesis from the leaves. During ripening the sucrose molecules are hydrolyzed (separated) by the enzyme invertase into glucose and fructose. By the time of harvest, between 15 and 25% of the grape will be
Late harvest wine Late harvest wine Late harvest wine is wine made from grapes left on the vine longer than usual. "Late harvest" is usually an indication of a sweet dessert wine, such as late harvest Riesling. Late harvest grapes are often more similar to raisins, but have been naturally dehydrated while on the vine. Botrytis cinerea, or "noble rot", is a mold that causes grapes to lose nearly all of their water content. Wines made from botrytis-affected grapes are generally very sweet. Botrytis cinerea is a fungus that affects many wine grapes and causes them to shrivel into moldy raisins. The fungus