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
Quinta classification of Port vineyards in the Douro Quinta classification of Port vineyards in the Douro The Quinta classification of Port vineyards in the Douro is a system that grades the "terroir" and quality potential of vineyards in the Douro wine region to produce grapes suitable for the production of Port wine. In Portuguese, a "quinta" is a wine producing estate, which can be a winery or a vineyard. While other wine classification systems may classify the winery (such as the 1855 Bordeaux classification), the Douro quinta classification is based upon the physical characteristics of the vineyard. The classification system is run by the "Instituto dos Vinhos do