What are tannins?

We often describe tannins as soft, velvety, aggressive; many terms are used, but what many people wonder is: What are tannins?

Tannins function as a defense mechanism against pests and predators; they are found mainly on the outer parts of various types of plants, in the case of grapes, in the skin. Tannins cause astringency and have a bitter taste.

During the fermentation process, the wine comes into contact with the grape skins, extracting color and tannins (structure). In excess, tannins can make the wine unpleasant, thus creating the need to "balance" or "soften" them. On the other hand, when paired with certain dishes, they contribute to making both the dish and the drink more flavorful.

There are grapes that are naturally rich in tannins because they have thicker skins, such as Tannat and Cabernet Sauvignon, which are typically responsible for well-structured wines rich in tannins. Pinot Noir, on the other hand, has thinner skins and therefore doesn't have the same tannic potential as the previously mentioned varieties.

Besides the grapes, the tannins in wine are also extracted from aging in oak barrels. The wood contributes tannins, and during the time the wine spends inside it, its tannic content increases. The newer the barrel, the more tannins it contributes.

Regarding white and rosé wines, tannins are few or even non-existent, as the skins are separated early in the process. In the case of Segredos da Adega Chardonnay, a white wine aged for 12 months in oak barrels, its tannins are imperceptible compared, for example, to Segredos da Adega Tannat.