Sweet-tasting, crystalline food that is obtained from various plants such as sugar cane or sugar beet. Depending on the number of carbon atoms in a sugar molecule, there are names pentoses (5 atoms = chemical formula starting with C5) and hexoses (6 atoms = C6). In the metabolism of the human body, the sugars are oxidized, which releases energy when heat is released, which causes motor activity. Most plants produce sugar through that photosynthesis in the form of sucrose and store it in the cells. Part is in Strength converted and stored in trunk and roots.
Other plants such as the grapevine split the sucrose into its components glucose (Dextrose) and fructose (Fructose) and store it in the berries of grapes, Both types of sugar are so-called monosaccharides and count among the hexoses. In the fermentation they are 90% immediate in ethanol and carbon dioxide converted, which is faster with glucose. Fructose sweetens many times as much as glucose and also dominates in residual sugar, The arabinose, rhamnose, ribose and xylose, which are among the pentoses, cannot be fermented or can hardly be fermented and are retained as residual sugar.
in the grape there are also traces of higher quality types of sugar (multiple sugar) that disaccharides, These include cane sugar and beet sugar (chemically identical), which are also called sucrose. In contrast to fructose and glucose, they are first extracted from the enzyme invertase split into their building blocks fructose and glucose and only then converted into alcohol and carbon dioxide. As a rough rule of thumb, the fermentation from 10 g sugar in 1,000 g must 0.66% vol alcohol content result. As a rule, 16.5 g / l for white wine and 18 g / l sugar for red wine have an alcohol content of 1.0% vol (see a conversion table below Mostgewicht ).
However, it should be noted that the sugar in the must never fully fermented, but always one residual sugar remains. In sweet wines is due to early fermentation a relatively high sugar content given. Sugar in various forms may be used in compliance with the legal provisions applicable in the respective countries enrich (increase the alcohol content in the not yet finished wine) and to sweetening (increase residual sugar in the finished wine). Sugar is an essential, qualitative component of the must or, depending on the type of wine, also wine. The phenomenon that the subjective perception of sweetness in wine can differ greatly from the analysis values is under the keyword sweet described. For the other ingredients in wine, see below total extract, See also under ICUMSA and reducing sugar,
Complete lists of the numerous vinification measures or cellar techniques, as well as the various types of wine, sparkling wine and distillate regulated by wine law are under the keyword winemaking contain. There is extensive wine law information under the keyword wine law,