What are tannins, and how do they impact wine?

Tannins are compounds derived primarily from grape skins, seeds, and stems, and they play a crucial role in the structure and mouthfeel of wine. They are polyphenolic compounds that can create a sensation of dryness in the mouth, often described as astringency. This tactile feeling enhances the wine's body and complexity, making it feel fuller and richer. Tannins also contribute to the aging potential of wines, as they can evolve over time, softening and integrating with other components such as fruit flavors and acidity.

The correct understanding of tannins helps wine enthusiasts appreciate the importance of these compounds in red wines, where they are most prominent. They balance the sweetness of fruit, moderate acidity, and contribute to the overall harmony of the wine. While they play a significant role in the structural integrity of the wine, they are not related to sweetness, flavors, or acidity in the same way as the other choices suggest.