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
Phenolic content in wine grapes known as teinturiers, such as Alicante Bouschet, which have a small amount of anthocyanins in the pulp that produces pigmented juice. There are several types of anthocyanins (as the glycoside) found in wine grapes which are responsible for the vast range of coloring from ruby red through to dark black found in wine grapes. Ampelographers can use this observation to assist in the identification of different grape varieties. The European vine family "Vitis vinifera" is characterized by anthocyanins that are composed of only one molecule of glucose while non-"vinifera" vines such as hybrids and the American "Vitis labrusca" will