When you eat unripe and tannin-rich fruits, or drink a particularly tannic red wine, you feel an astringent sensation in your mouth, as if the oral cavity suddenly becomes dry and rough.
A wine that sets teeth on edge is a wine rich in tannins. Some red wines contain particularly high quantities, while the tannic content of white wines is considerably lower. Part of these tannins is present in grape skins and grape seeds (grape seeds), but an important part can also be released from the wooden barrels where the wine is left to mature.
Like all fruits, even the grapes are decidedly richer in tannins when they are sour; for this reason, the collection period is essential for the production of a wine whose specific characteristics are sought. Peel-must contact time is also very important; in fact, the quantity of tannins that pass from the skins to the must increases as well.