Tannins are compounds found in the skin, seeds, and stems of grapes that contribute to the mouth-coating sensation in certain wines. These compounds are part of what gives red wines their distinct astringency and structure, and they play a significant role in shaping the overall flavor profile of a wine.
What are tannins?
Tannins are polyphenolic compounds that are naturally present in many plants, including grapes. In wine, tannins are extracted from the grape skins, seeds, and stems during the winemaking process. Tannins can also be found in oak barrels, which are often used for aging certain wines. Tannins are responsible for the dry, puckering sensation you may feel in your mouth when drinking certain wines, especially red wines.
How do tannins contribute to mouth-coating sensation?
When you drink a wine that is high in tannins, you may notice that your mouth feels dry and astringent after each sip. This mouth-coating sensation is caused by the tannins binding to the proteins in your saliva and on the surface of your mouth. This binding action creates a dry, puckering feeling that is often described as “grippy.”
Here’s how tannins contribute to the mouth-coating sensation in certain wines:
- Tannins bind to proteins: Tannins have a strong affinity for proteins, which are abundant in your saliva and the lining of your mouth. When you drink a wine that is high in tannins, these compounds bind to the proteins in your mouth, creating a dry sensation.
- Interact with taste receptors: Tannins can also interact with your taste receptors, particularly those responsible for detecting astringency. This interaction can enhance the perception of astringency in the wine, contributing to the mouth-coating sensation.
- Structural role: Tannins play a structural role in wine, providing a framework for the other flavors and aromas in the wine to build upon. This structural support can contribute to the overall mouthfeel of the wine, including the sensation of coating your mouth.
Types of tannins
There are two main types of tannins found in wine:
- Seed tannins: These tannins are extracted from the seeds of the grape during winemaking. Seed tannins are typically more bitter and astringent than skin tannins.
- Skin tannins: These tannins come from the grape skins and are responsible for the color, flavor, and mouthfeel of the wine. Skin tannins are generally softer and more approachable than seed tannins.
Impact of tannins on wine aging
Tannins also play a crucial role in the aging potential of a wine. Over time, tannins can polymerize, or combine with other compounds in the wine, to form larger molecules. This process can help soften the tannins and mellow out the mouth-coating sensation, leading to a smoother, more integrated wine.
Here’s how tannins impact wine aging:
- Softening effect: As tannins polymerize over time, they become less aggressive and more integrated into the wine. This can help soften the mouth-coating sensation and improve the overall balance of the wine.
- Development of secondary aromas: During aging, tannins can also interact with other compounds in the wine to develop complex secondary aromas and flavors. This can enhance the overall drinking experience and contribute to the wine’s complexity.
- Age-worthiness: Wines that are high in tannins are often considered age-worthy because the tannins provide structure and support for the wine to develop and evolve over time. As the tannins soften and integrate, the wine can reveal new layers of flavor and complexity.