What are Tannins in Wine

Tannins are a class of astringent, polyphenolic biomolecules found in various plants, including grape skins, seeds, and stems. Tannins contribute to the taste, texture, and structure in wine, particularly in red wines. They are responsible for the astringent and bitter qualities in wine, which can add complexity and balance. Tannins also play a role in the aging process of wine, as they have antioxidant properties.

Tannins in Red and White Wines

Red wines typically have higher levels of tannins compared to white wines due to the extended contact between the grape juice and the skins, seeds, and stems during fermentation. White wines usually have lower tannin levels because they are immediately pressed rather than macerated.

Tannin Sources in Wine

Tannins in wine can come from four primary sources: grape skins, seeds, stems, and oak barrels used during aging. The extraction of tannins from these sources depends on the winemaking process, such as the duration of skin contact, maceration, and fermentation.

Tannins and Wine Taste

Tannins can have a complex taste in wine, adding bitterness and astringency. They can be described as ripe, supple, velvety, soft, silky, or sweet, as well as aggressive, chewy, harsh, green, angular, or searing. The perception of tannins in wine can vary based on the grape variety, winemaking techniques, and individual taste.

Tannins and Wine Aging

Tannins play a crucial role in the aging process of wine. Their antioxidant properties help preserve the wine, and over time, tannins can polymerize and bind to anthocyanins, resulting in a lighter color and reduced bitterness.

Wines High in Tannins

Some grape varieties are known for producing wines with high tannin levels, such as Cabernet Sauvignon, Monastrell, Montepulciano, Nebbiolo, Petit Verdot, Petite Sirah, Sangiovese, and Shiraz.

In Summary

Tannins are essential components of wine, contributing to its taste, texture, and structure. They play a significant role in red wines and are derived from grape skins, seeds, stems, and oak barrels. Tannins also influence the aging process of wine, and their presence can vary depending on the grape variety and winemaking process.