The term tannins is derived from the French tanin for tannin. It is a natural chemical compound that is also found in coffee, tea, in the wood and bark of oak, birch and chestnut trees and, of course, in grapes.
Over thirty different tannins are commonly used in viticulture today. Depending on their content and structure in the wine, some of these tannins have a positive influence on wine quality. However, there is also a whole range of tannins that are classified as rather unfavorable for the refinement of wines.
The tannins themselves have no taste of their own, at best they can be described as having a very light, tart or bitter note. It is only when they come into contact with the mucous membranes in our mouth that the typical furry taste develops, which is also known in wine jargon as astringent or astringent. Tannins also influence how we perceive the taste of other compounds in wine. They make the wine appear soft, round, leathery, sharp and aggressive or coarse – they can therefore be confidently described as the mouthfeel of wine. They also influence the color of the wine.
Tannins naturally play a much greater role in red wines, as they occur in a much higher concentration in red wine grapes. However, they are of course also found in white wine grapes. When red wine is pressed, they not only enter the must from the grape skin but also via the stems and rappels. In particular, the tannins extracted from the skin are responsible for the deep red to red-brown color of the later wine. It is obvious that the amount of tannic acid contained in the wine also depends on the duration of the mash fermentation, also known as the maceration time. Another important factor is the temperature that prevails during fermentation. The warmer the temperature, the easier it is for the tannins to separate from the skin of the crushed red wine grapes. If the wine is stored in oak barrels, further tannins are released into the wine from the oak wood.
Last but not least, the respective grape variety also has an influence on the tannin content. For example, the Pinot Noir grape has a significantly lower tannin content than the Cabernet Sauvignon or Syrah grape. Regardless of the respective grape variety, the tannin content is highest in those grapes that come from high altitudes where the sunlight and solar radiation are more intense. But even then, not all tannins are the same. This is because the quality of the tannins also depends on the degree of ripeness of the grapes. Tannins not only play an important role in the later wine. Even in the grapes, they perform multiple protective functions. On the one hand, they protect the grapes from too much sunlight and from possible predators and, on the other hand, thanks to their antiseptic properties, they also have a protective effect against putrefactive bacteria.
However, it is a misconception that tannins influence the shelf life of a wine. Rather, the tannin content of a wine says something about how long it should be stored until it offers its full taste and enjoyment experience.
