Sweet-tasting, crystalline food, which 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 the 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, releasing energy while releasing heat, which causes motor function. Most plants produce sugar by the photosynthesis in the form of sucrose and store it in the cells. Part will be in Strength converted and stored in trunk and roots.
Other plants such as the others grapevine split the sucrose into its components glucose (Glucose) and fructose (Fructose) and store them in the berries grapes, Both sugars are so called monosaccharides and are among the hexoses. In the fermentation They are 90% directly in ethanol and carbon dioxide this is done faster with glucose. The fructose sweetens many times as much as the glucose and also dominates in the residual sugar, The arabinose, rhamnose, ribose and xylose, which belong to the pentoses, are not or hardly fermentable and remain as residual sugars.
in the grape There are also traces of higher-value sugars (multiple sugars), the disaccharides, These include cane sugar and beet sugar (chemically identical), which are also called sucrose. Unlike fructose and glucose, they are first released from the enzyme invertase split into their building blocks fructose and glucose and then converted into alcohol and carbon dioxide. As a rough rule of thumb that is through the fermentation from 10 g of sugar in 1,000 g of must 0,66% vol alcohol content result. As a rule 16.5 g / l of white wine and 18 g / l of red sugar have an alcohol content of 1.0% vol (see a conversion table below) Mostgewicht ).
It should be noted, however, that the sugar in the must never completely ferment, but always residual sugar remains. In sweet wines is a relatively high due to early fermentation sugar content given. Sugar in various forms may be used in compliance with the applicable legal regulations in each country enrich (increase the alcohol content in the not yet finished wine) and to sweetening (increase residual sugar in the finished wine) can be used. 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 below the keyword sweet described. For the other ingredients in wine, see total extract, See also below ICUMSA and reducing sugar,
Complete listings of the numerous vinification measures and cellar techniques, as well as the various wine-regulated wine, sparkling wine and distillate types are under the keyword winemaking contain. Comprehensive information on wine law is available under the keyword wine law,