Tannins

An Explanation of Tannins

After recent wine tastings with friends, I found that “tannins’ were a topic of interest due to the fact that people either liked wines with high tannins or totally disliked them. There were 3 main questions during the tastings about tannins which I hope this article answers.

Question: What are tannins?

Answer: Technically speaking, tannin is type of chemical named “polyphenols”. Polyphenols are found in many fruits and vegetables. They give these foods their colors and contribute to flavor, aroma and bitterness. They contain powerful anti-oxidants and are a source micro- nutrients. Tannins in wine are discernable as a bitter or astringent character. The woody, rough and gritty sensation when drinking wine is tannin. Many people comment that a wine is especially dry when drinking wine high in tannin. Tannin has nothing to do with the dryness of wine. Tannin appears in different levels (low, medium or high) in different wines. Wines with low tannin levels are often said to be “smooth”, while wines with high tannin levels are often said to be “rough”. Tannins in wine add structure and body.

Question: Where do tannins in wine come from?

Answer: The tannins in wine come from the stems, skins, and pips (seeds) of the grapes.

Question: Since all wines have stems, skins and pips, why don’t all wines have tannins.

Answer: All wines do have tannins but some wines only have trace amounts. The amount of tannin in wines is determined by how long the juice has contact with skins, stems, and pips during the maceration and fermentation steps when making wine. When making white wine the stems and skins are removed from the juice as quickly as possible, thus minimizing the amount of tannin. When drinking white wines, there should little to no sensation for tannin. In red wines, on the other hand, tannin levels vary from low to medium to high depending on the grape variety or varieties used to produce the wine in addition to time in contact with skins, stems and pips during maceration and fermentation. The following table provides some guidance on tannin levels for common red wines.

Tannin impact in wine can be lessened by decanting. The longer a wine is decanted, the more the tannins will be softened. Also, aging wines will soften tannin. The longer a wine is aged, the softer the tannins will become.