How does high tannin content generally express itself in a wine's sensory experience?

High tannin content in wine is primarily characterized by a drying sensation in the mouth, which can be easily perceived after swallowing or spitting out the wine. This effect results from tannins' astringent qualities, which interact with proteins in the saliva and create a tactile feeling on the gums and the inner cheeks. This textural aspect of tannins is critical in red wines, particularly since they come from the skins and seeds of grapes, making them more pronounced than in most white wines.

While sweetness, fruitiness, and smooth mouthfeel are essential components of wine, they are influenced by different factors. For instance, sweetness comes mainly from residual sugars, fruitiness derives from the grape variety and ripeness, and a smooth mouthfeel is often a result of lower tannin levels or the presence of other elements that soften the wine's character, such as aging in oak barrels or a higher alcohol level. Thus, the high tannin content specifically contributes to that distinctive drying sensation, making it the key characteristic being highlighted in this context.