What are wine tannins?

If you enjoy a good glass of wine, you’ve probably searched for information or asked experts about the characteristics of a particular bottle. But… what are wine tannins?

This is a concept that is becoming increasingly popular, yet many people still don’t fully understand what it really means.

What are wine tannins?

Tannins provide color and structure to a wine. We notice them in our mouth because they create tactile sensations, such as smoothness.

They are natural chemical compounds that contain polyphenols, which include essential elements responsible for the wine’s color and structure.

Where do tannins come from?

Tannins are found in the skin of grapes used for winemaking. Some varieties, like Cabernet Sauvignon, have thicker skins and, therefore, contain more tannins.

The amount of tannins in grapes is also influenced by the harvest conditions—in drier years, grapes develop thicker skins, leading to higher tannin content.

Tannins are also present in the seeds and stems of the vine, meaning the grape juice remains in contact with them during the pressing process.

Additionally, wood is another source of tannins, especially oak. As a result, aging wine in oak barrels allows tannins to dissolve into the wine.

Astringency

We can easily perceive tannins through the dry, rough sensation they create in the mouth, especially on the tongue and gums. This is particularly noticeable in wines with high levels of robust tannins.

The mouthfeel of a wine with these characteristics is dry, astringent, and somewhat rough. To compare, the sensation is similar to drinking unsweetened black tea.

Types of tannins

To identify and analyze different types of tannins, we should hold the wine in our mouth for about 15 seconds. The sensations we perceive help us determine which variety we are tasting and, therefore, the wine’s aging potential.

• Sweet and velvety tannins leave a mild dryness on the gums, indicating that the wine is ready to drink.
• Harsh tannins cause significant dryness, to the point where it may be difficult to restore saliva production.
• Silky tannins leave the palate feeling juicy, suggesting that the wine still has aging potential and has not yet reached full maturity.

Tannins in red wine

Red wines are the most tannic, meaning they contain a higher concentration of tannins than other types of wine.

This is because, during winemaking, the must ferments in contact with the skins, seeds, and sometimes stems of the grape—all primary sources of tannins. These compounds add structure, complexity, and aging potential to the wine.

Tannins can be easily detected in red wines through:

• Deep, intense color.
• Firm structure.
• Mouthfeel, which can range from slightly rough to silky and velvety, depending on grape variety and aging time.

Unlike reds, white wines contain very few tannins, since they are usually fermented without skin contact. However, oak-aged white wines can acquire mild tannins from the wood, adding body and complexity.

Tannins and wine aging

Tannins play a key role in the evolution of red wines over time.

• In young wines, tannins tend to be more aggressive and drying.
• With aging, tannins soften and round out, resulting in a smoother, more balanced experience.

The different types of red wines are distinguished primarily by their tannin content, which is directly related to the grape variety used in their production.

Understanding how tannins influence wine helps us appreciate its unique characteristics and enjoy it to the fullest.