Description (also drying or unripe tannins/tannins) for the negatively understood mouth-drying, rough or strongly astringent effect in the context of a wine response. However, this is not a taste sensation, but a trigeminal sensation (concerning the sense of touch). These are particularly fine-grained tannins, which give an impression of fine sand in the mouth and have a rather unpleasant "hard" taste. They are also called "bad tannins". As a rule, this does not change even with longer maturation of the wines. The cause is unripe grapes. In contrast, the "good or ripe tannins" are coarse grained and give a "soft" impression. There is an original way of checking whether the tannins are "good" or "bad". If you can whistle after tasting a tannic wine, they were "good". Another characteristic is that they stimulate the salivary flow. A term used in the USA for a too pronounced tannin taste is tannin to loose.