The reduction (see there) is a complex chemical process. In the winemaking is understood by a reductive expansion the most complete exclusion of the for the metabolism of microorganisms necessary oxygen and thus prevention of unwanted oxidation, This claim is made by the shortest possible transport routes and processing times of grapes, must and wine with cool ambient conditions Press, of the must treatment, of the fermentation, the expansion in hermetically sealed containers (steel tanks) up to bottling Taken into account.
This is also supported by measures such as sulphurize. beautiful and filtration, Through a reductive expansion is the colour, as well as the odor and the taste that is, it greatly influences the overall aromas of a wine. The wines are characterized by a typical lively. fruity and pure taste with pronounced flavors (Primary aromas) as well as from white to light yellow color (the iron-containing pigments are oxidizable and give a darker color). These taste and smell impressions are in the positive sense as reductive notes designated.
A reductive expansion takes place mainly at White wines and sparkling wines, In Germany and Austria this is the rule. There are exceptions mainly in more southern areas like Italy and Greece. The process must, however, be controlled, as too rigorous, strong oxygen to the formation of volatile sulfur compounds such hydrogen sulfide and thiols (Mercaptans) can lead to reductive grades. To a lesser extent, this is called a so-called " Stinkerl "Possibly still accepted. At higher concentrations, however, these are negative taste directions like Muffton or the dreaded ones sulfurous off (Schwefelböckser) and mean one wine faults, By ventilate or. Decant can such a wine possibly be brought back into balance (see under this topic under reduction flavors ).
The complex, chemical changes during the bottle aging or. aging of a wine are sometimes also referred to as reductive expansion or reeductive process (see also under micro-oxygenation ). In contrast to the reductive stands the oxidative expansion with a metered oxygen contact. This is usually done at red wines with frequent barrel aging,
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,