What do tannins do?

Answered by Dustin Gorski

Tannins, found in various plants, are compounds that serve multiple purposes in nature. As mentioned, one of their main functions is to act as a deterrent for animals from consuming a plant's fruit or seeds before they are fully ripe. This mechanism helps ensure the plant's survival by allowing its fruits and seeds to mature fully and disperse effectively.

When it comes to taste, tannins are responsible for the astringent, mouth-coating sensation we experience when biting into certain fruits like unripe pears or plums. This dry, puckering feeling is a result of the tannins binding with proteins in our saliva, causing them to precipitate and form a thin film on the surface of our mouths. This reaction is why tannins are often described as having a “drying” or “rough” effect on the palate.

In the world of beverages, tannins play a significant role in the flavors and textures of both and . In wine, tannins primarily come from the grape skins, seeds, and stems, as well as from the in which the wine is aged. They contribute to the wine's structure, bitterness, and astringency, giving it a firm and sometimes gripping mouthfeel. Tannins also act as natural preservatives, helping wines age gracefully and develop complex flavors over time.

As a sommelier, I have encountered wines with varying levels of tannins. For example, young red wines, particularly those made from grape varieties like Cabernet Sauvignon or Nebbiolo, tend to have higher tannin levels. These wines can feel quite astringent and may benefit from aging to soften and integrate the tannins, allowing the wine to become more harmonious and approachable.

On the other hand, white wines generally have lower tannin levels, as they are typically made without prolonged contact with grape skins during fermentation. However, some white wines, such as certain styles of orange wine or skin-contact white wines, can exhibit noticeable tannins due to extended skin maceration.

In the world of tea, tannins also play a crucial role. When tea leaves are steeped in hot , tannins are released, contributing to the tea's flavor and mouthfeel. Black teas, in particular, are known for their higher tannin content, resulting in a robust, full-bodied cup. Green teas, on the other hand, generally have lower tannin levels, leading to a smoother and lighter taste.

It's worth noting that while tannins can provide desirable characteristics in beverages like wine and tea, excessive amounts can lead to an unpleasant, overly astringent or taste. This is why winemakers and tea producers carefully manage their processes to strike a balance between tannin extraction and overall flavor profile.

Tannins serve as a defense mechanism in plants, deterring animals from consuming unripe fruits or seeds. They create an astringent sensation when consumed, leaving a dry, mouth-coating feeling. In wine and tea, tannins contribute to the structure, bitterness, and mouthfeel of the beverages, adding complexity and aiding in preservation. However, the level of tannins must be carefully managed to ensure a pleasant drinking experience.