Tannins (tannins) occur mainly in the grape stalk, the kernels and the skins. The pulp does not contain tannin. White wines contain no tannins, as the grapes are pressed immediately and so the tannin does not have time to pass from the solid ingredients in the must. Thus, the occurrence of tannin is limited to the red wines. However, the grape varieties are relevant for the tannin content.