What are tannins?


Tannins in a wine is indicated on almost every red wine label. What are tannins and is it beneficial for the flavour of wine or is it solely to ensure that wine is preserved longer?


Tannins are elements in wine that originates from the wooden barrels in which wine was aged or from grape skins, seeds and stems during the yeasting process. In some cases tannins are added artificially.

Tannins have a few important functions when it comes to making wine. By putting a stop to the growth of bacteria, tannins ensure that wine is preserved longer. It causes wine to age gradually and the development of flavours and aromas to happen in the desired tempo.

In principal, a wine maker can decide how much tannins are added to a wine. This occurs during the yeasting process of the grape skins. The longer the yeast process with the skins, seeds and stems continues, the more tannins are released in a wine, the darker the wine colour gets. The large quantity of tannins ensures for a longer preservation of wine. However, it also causes the duration of the aftertaste to be longer.

Tannins occur in red wine as well as in white wine. However, red wine contains more tannin than white wine. This is because of the way red wine is produced. Compared to white wine the grape skins, seeds and stems in red wine stay in red wine for the total duration of the yeasting process. With white wine, the grape skins, seeds and stems are immediately separated after being pressed for grape juice. For this reason, white wine can’t be preserved as long as red wine.

The best way to experience the flavour of tannins, is to bite down on a grape seed and hold it in your mouth or drink a big sip of cold tea. The flavour of this is bad and the corner of your mouth will want to contract. When people taste wine that contains a lot of tannins, it will be described as sour. However, sour would not be the correct word to describe this flavour. A more fitting description would be, dry or bitter.

A surplus of tannin causes a wine to taste hard and dry. However, nice and ripe tannins contributes to a nice structure of wine when it’s in the mouth. That’s why it is essential for the wine maker to find a good balance between a long shelf-life and the flavour of wine.