Tannin is a chemical substance present in plant extracts, belonging to the polyphenol family, common in plants and trees.
In grapes we find tannins in the skin (in dark-skinned grapes), in the pips (the seeds inside the grape) and in the stalk (the stem that holds the bunch).
It is thanks to the tannins that the wine, especially the red, keeps better, and, again thanks to the action of the tannins, we will have the variegated nuances that we so much appreciate in red wines.
At the time of harvest it is important that the stalks are removed before pressing the grapes and that the same (crushing) takes place in a soft, almost delicate way: in this way it will be avoided that too green or too strong tannins from the grape seeds are released from the stalks. , which could negatively affect the final result.
In the cellar, the time of maceration and rest of the wine on its skins will have a timing decided by the oenologist, based on the type of color, body, structure and astringency that will then be characteristic of that wine, but also to give the same wine a greater storage capacity and duration over time.
Finally, it will be aging in cask to give the definitive and final contribution of tannins. In fact, it is the microcirculation of oxygen that occurs with wood that transfers aromas and olfactory complexity to the wine. “In the small barrel there is the best wine”: it is no coincidence that the famous popular saying was born, in fact the smaller the barrel (barriques or keg) the higher the ratio between wood and wine.
We have seen that tannins are present in trees, so here is the importance of the wood in the barrels. An oak barrel will release more tannins over time than other woods used to make barrels, be it oak, chestnut, cherry, maple. In new barrels the tannins will be fresh and more evident, in the most used barrels soft and round tannins will be released (Amarone wines are practical examples).
But what is the most evident characteristic of tannin? It is astringency.
That feeling of dryness in the mouth, lack of salivation or, to give the usual figurative example, the result of biting an unripe persimmon. This “allappante” sensation is a quality of the wine and not a defect, it is what makes a red wine easily paired with liquid dishes such as soup, or juicy and fatty dishes such as grilled meat.
An excellent combination is a Chianti Classico with a beautiful Florentine steak where the soft and dry tannins of the wine will prepare the palate for the strong flavor of the meat.