Concha y Toro

Francisca Jara 14/09/2022

All about wine

What are tannins and what is their role in wine?


Have you ever had a cup of tea that tasted too strong? So much so that it felt rough on your tongue? Well, that astringency is due to the tannins in the tea. Tannins are not a component only derived from the wine process, but phenolic compounds present all over in nature.

Tannins can be found in the bark of trees such as oak, spices like cinnamon, plants such as rhubarb or tea, and in the skin of fruits like blueberries, pomegranates, acai, cocoa, coffee, walnuts and of course, grapes. Its reason for existence is nothing more than to protect these fruits and plants from external agents (from microorganisms to animals) so that they can develop, mature and fulfill their natural cycle.

How do tannins get into wine?

In the specific case of wine, tannins come from the stems of the vine, the skin and the seeds of the grapes, released when they come into contact with the juice during the pressing of the grapes. Depending on the maceration time of the skins with the juice, a wine will have a greater or lesser load of tannins. If this time is prolonged, the wine will have more tannins. We refer to this characteristic when we say that a wine is tannic. 

How do we identify them? By tasting the wine and evaluating how astringent or dry it feels in the palate after ten seconds. However, depending on their tannin levels and how they are worked, wines can be described as silky, smooth, rough, green, bitter, elegant. That is, whether they are pleasant or not.

Reds are the Wines with the highest tannic load. Certain varieties such as Tannat, Cabernet Sauvignon, Malbec, Nebbiolo, Syrah, Merlot, Tempranillo and Mouvèdre have a higher concentration of tannins because they are left in contact with their skins for a much longer period to obtain their colour. In the case of white wines, maceration is much shorter, which in turn produces wines with less colour and weaker tannins.

However, tannins are not only obtained from the grapes. They are also transferred from the oak barrels, which play an important role in the complexity of wines. A red wine aged in new French oak barrels, such as the wonderful Carmenère Carmín de Peumo, stands out because it fills the mouth with its underlying tannins. They are also related to its deep dark red colour with violet hues and its great body. White wines such as Amelia Chardonnay, with one year of aging in barrels, get their tannins from the oak rather than from the grape, also providing an attractive structure and complexity.

Foto: Ashley Bird en Unsplash

Their benefits

In addition to the colour, structure, and complexity that tannins impart to the wine, it is believed that their presence helps them age better. Although this theory is still under discussion, the truth is that as wines develop, their tannins tend to become softer thanks to the polymerization process. This is the case of wines such as Terrunyo Cabernet Sauvignon, with silky tannins and great aging potential.

Tannins are also a natural antioxidant that protects not only wine but also us humans, with anti-inflammatory and antioxidant properties that can help us prevent degenerative and cardiovascular diseases and cellular aging.