After fermentation, fruit sugar can remain in the wine, because the yeasts are no longer effective, or because the fermentation was artificially interrupted. This is referred as residual sugar. Depending on the proportion of residual sugar the wine is called dry, semi-dry, half-dry or sweet. 

The flavour of wine is not only dependending on residual sugar. The aromas of the grape variety, the cultivation in the vineyard and the expansion in the wine cellar contribute to the individual aromas of a wine. An important flavor factor in the wine is the harmony of tartaric acid, residual sugar and alcohol content. A dry wine with high alcohol content can taste mild, while sweet wines with a high acidity often appear semi-dry. For red wines, the vegetable tannins from the grape bowl and the kernels also play an important role. 

The term "mild" is used for low-acid wines or for sweet wines with a residual sugar content of more than 46 g / l, in which acid falls into the background.