Tannins are chemical compounds that belong to a larger group of compounds called polyphenols (there are over 8,000 different types). Some of the most common polyphenols are acids, flavonoids, stilbenes, and lignans. They exist in numerous plant based foods and originate from the plants bark, stems, seeds, and skin. In early civilisation, tannins were used to preserve leather, making it soft and sturdy. Humans consume tannins by drinking wine, tea, eating nuts, chocolate, and certain vegetables such as spinach.
Where do Wine Tannins come from?
Wine tannins are produced from grape skins, seeds, stems, oak barrels, and additives (synthetic tannins that can be used to enhance a wine). Grape skins are the primary source of tannins in wine. During the growing season, the skins act as a sunscreen, protecting the developing fruit.
Grapes that are exposed to more sunlight will produce wines with a higher concentration of tannins. The smaller the grape, the larger the concentration of tannins.
During the growing season, winemakers work tirelessly in the vineyards manipulating the amount of tannins that are produced in the grapes by using different techniques to soften and reduce excess tannins. Irrigation and canopy management (leaves that cover the grapes), giving the grapes more shade during the hottest periods of the growing season have a big effect on the amount of tannins that are produced. One of the main challenges of a good winemaker is to create a wine with a well-balanced tannic structure that expresses the style of wine that they want to create - a process that starts in the vineyard and finished when the wine is bottled.
What is a Tannin?
Tannins are relatively small and help to extend the life of a wine once it has been bottled. The tannins in bottled wine combine with other elements and form larger compounds which will eventually separate from the liquid solution and form a sediment. As a general rule, the older a bottle of wine, the softer the tannins will be, there will also be more sediment created in the bottle.
What Wines have High Tannins?
Red, rosé, and white wines all contain tannins. White and rosé have very subtle tannins as there is limited contact with grape skins during the fermentation process. Red wines on the other hand often have a very high concentration of tannins because they undergo the maceration process. This is the period during fermentation when the grape juice is in direct contact with the grape skins (often for several days) to obtain its red color. The grapes skins have very concentrated tannins and the longer the fermenting grape juice is in contact with the grape skins, the higher the final tannin levels will be.
Tannins and their role in the wine aging process - How do Tannins affect wine?
Have you ever opened a bottle of wine and then heard, “this is very tannic?” Tannins can be expressed through number of spectrums, from exceptionally harsh to exceptionally soft. The younger a bottle of red wine is the harsher the tannins will be. Tannins are commonly described as a being a bitter or dry sensation that is felt in the mouth when drinking red wine. Though they may taste unpleasant at first, tannins are very important and give structure and texture to wine and directly affect the overall sensation and taste of the wine in the drinkers mouth.
Many of today’s wine drinkers often do not want to wait years for their bottle of wine to have been properly aged and therefore winemakers have adapted by using techniques that help to soften the tannins so that wine is easily drinkable when it is first released. When the wine comes into contact with oxygen, the tannins start to soften which makes the wine taste more silky and smooth which makes it much more enjoyable to drink. This is often why it is recommended to decant or aerate a bottle of red wine for up to an hour before serving it.
Do Tannins have Health Benefits?
The consumption of tannins (polyphenols) can have health benefits as there are certain types that have antioxidant and anti-inflammatory properties. Various studies have been conducted suggesting many possible health benefits such as giving added protection against certain diseases such as diabetes, cardiovascular and neurodegenerative diseases and certain cancers. Perhaps the presence tannins in the wine could be the reason that different studies have suggested that moderate daily consumption of red wine have health benefits. However there is still not enough conclusive evidence to prove this hypothesis.
Tannins are very important not only for the structure and tastes that are present in a glass of wine, but also play a very important role in in the aromatic expression and longevity of a wine and may even have longterm health benefits!