**1. Introduction**

Studies from several countries show rising alcohol contents for wine over the last decades. There are many factors contributing to that phenomenon. Better viticultural practices and improved plant material lead to elevated sugar levels in grapes. In higher alcohol yields of selected yeast strains, modern vinification techniques furthermore lead to an increase in alcohol. The other driving factor for that development is the climate change which cannot be turned back that easily as the other factors. With rising alcohol contents, some wines appear outbalanced and alcoholic which can lead to the consumers' rejection. Additionally, enologists run into fermentation problem caused by elevated sugar contents of grape must and excessive alcohol contents at the end of fermentation. Especially the production of sparkling wine requires moderate alcohol contents to avoid problems with second fermentation.

As a result alcohol management has taken a new direction, from mainly maximizing alcohol contents to minimizing alcohol levels, as well. There are several physical methods available for reducing the alcohol content to a targeted level. They are either based on membrane processes such as osmotic distillation and reverse osmosis coupled with another treatment or on distillation under vacuum. The physical methods for alcohol reduction allow a targeted optimization of the alcohol content according to marked demand or to adapt to taxation and import tariffs based on actual alcohol content of the wine.
