Tannins

What Are Tannins?

Tannins (also called tanning agents or polyphenols) are natural plant compounds found in wine primarily in grape skins, seeds, and stems. They give red wine its characteristic structure, the slightly furry or astringent mouthfeel, and are crucial to a wine's aging potential.

Origin of Tannins

In wine, tannins come from various sources:

Grape tannins come mainly from the skins, seeds, and stems of the grapes. The longer the maceration period during fermentation, the more tannins are extracted. This is why red wines have far more tannins than white wines — in white winemaking, the juice is usually separated from the skins immediately after pressing.

Wood tannins come from aging in oak barrels (barrique). New barrels release more tannins than used ones. These wood tannins differ in taste from grape tannins and give the wine additional complexity, often with vanilla or spicy notes.

What Do Tannins Taste Like?

You don't taste tannins directly the way you do sweetness or acidity — you feel them in your mouth. They create a dry, slightly rough or furry sensation on the tongue and palate, similar to very strong black tea. This sensation is called astringency.

Depending on ripeness and quality, tannins can differ:

• Green, unripe tannins: Bitter, hard, aggressive — typical of wines from unripe grapes or overly long maceration
• Ripe, soft tannins: Velvety, silky, elegant — characteristic of high-quality wines from ripe grapes
• Well-integrated tannins: Over time, tannins soften and blend harmoniously with the other components of the wine

Role in Wine Maturation

Tannins are antioxidants and protect the wine from oxidation. This is why tannic red wines can often be cellared for many years or decades. Over time, tannins polymerize (bond into larger molecules), become softer, and partly settle as sediment at the bottom of the bottle. This process makes young, tannic wines more approachable and harmonious with age.

Tannic vs. Low-Tannin Grape Varieties

High tannin: Nebbiolo, Cabernet Sauvignon, Tannat, Syrah, Sangiovese Medium tannin: Merlot, Tempranillo, Cabernet Franc Low tannin: Pinot Noir, Gamay, Pinot Meunier, Portugieser

Tip: Tannins with Food

Tannins bind to proteins and fats in food, making them seem softer and more pleasant. This is why tannic red wines pair so well with steaks, roasts, or aged cheese — the fat in the food mellows the astringency, while the tannins "cut through" the fat in the mouth and cleanse the palate.