When it comes to red wines, you have often come across statements that they are “tanned”. Tannin is a bitter, palate-drying ingredient found in grapes, similar to that of long-brewed tea. Tannins are in the skin, stem, and core of the grape and are the most important components of red wine. It not only determines the color and texture of the wine, but also acts as a preservative by helping the wine to mature. While red wine is being produced, tannins in the shell and kernel pass into the wine during fermentation along with the color substances in the shell. After fermentation, tannins of oak are added to the wine if it is rested in wooden barrels. It can be said that the wine that comes out at the end of this whole process has more or less tannins; In fact, expressions such as that the tannins are rounded as a result of resting the wine for a suitable time, otherwise the tannins are angular. Black grapes that produce strong wines such as Boğazkere, Cabernet Sauvignon, Syrah, and Malbec can be counted among the most well-known grapes with high tannin content; Due to the protective properties of the grain, the wines produced from these grapes are also suitable for aging.