What are tannins?

Tannins are natural compounds found in wine, primarily derived from grape skins, seeds, and stems, as well as from oak barrels used in aging. They belong to a class of polyphenols and play a significant role in the taste, texture, and aging potential of wines. When we talk about the tannic structure that wines have, it is important to note that tannins are not a flavor profile, but rather a description of the mouthfeel you experience when drinking wines.  

Tannins are responsible for the astringency and bitterness in wine. When you taste a wine with high tannins, it can cause a drying or puckering sensation in your mouth, especially around your gums and tongue. This sensation occurs because tannins bind to proteins in your saliva and tissues, making them feel dry. They also contribute to the structure of wine, giving it body and a more robust mouthfeel. Wines with higher tannin content, like cabernet sauvignon, are often described as “full-bodied” and have a firmer, more intense texture. The presence of tannins helps balance the acidity and fruitiness in the wine, creating a more complex and harmonious taste. 

One of the most important functions of tannins is their preservation role. Tannins act as antioxidants, helping to protect the wine from spoilage and allowing it to age more effectively. Wines with higher tannin content, like many reds (cabernet sauvignon, nebbiolo, and syrah), often improve with age, as tannins soften and integrate over time, contributing to more complex flavors and smooth textures. 

Tannins are more abundant in red wines than in white wines because the grape skins are in contact with the juice during fermentation, allowing tannins to be extracted. White wines, on the other hand, are typically made without skin contact, resulting in lower tannin levels. Some tannins will also be introduced during the oak aging process, due to a presence of tannins in the oak.