Term for an unfermented and by means sulfur dioxide or filtration sterilized grape, This buried especially in cooler wine growing areas the already fermented wine to the acid to mitigate and the Residual sugar content to increase. The must is at best the same from which the wine was produced. Therefore a part will be before the beginning of the fermentation withdrawn, the sterile or completely free from yeasts must be in order to exclude a secondary fermentation. He must go before adding to the wine desulphurized become.
The term sweet reserve is used in part but also for the process of sweetening itself. The required amount can be determined by means of the so-called Cramer's Cross be calculated or (much easier) done by sweetening tables. In Austria is a sweetening in any form (including sweet reserve) at the quality level cabinet and for everyone Prädikatsweine forbidden. In Germany the addition of sweet reserve is also allowed for predicate wines, but this is only used by individual producers.