Elements of wine—tannin

Wine has five components that determine taste and quality: alcohol, acid, tannin, sweetness/dryness, fruitiness. Last weeks alcohol and acid; this week tannin.

Tannin, acidity, and alcohol comprise wine’s soul, with acidity most important in whites and tannin most important in reds.

Tannin is not really a taste, but a tactile sensation on your tongue and cheek. Drink tea brewed too long—the mouth-puckering sensation is tannin.

Tannin comes from skins, seeds, and stems. Red wine becomes red because of prolonged contact with these elements; white wines do not have this contact, so reds have more tannin than whites. Oak also has tannin; aging in oak barrels is another way wines gain tannin, although grape tannins and oak tannins are not the same. White wines made in stainless steel have very low tannin. Lack of tannin is why most whites are best young.

Different grapes produce different levels of tannin. Thin-skinned Merlot berries produce lower levels of tannin. Thick-skinned Cabernet Sauvignon berries produce high levels of tannin. Balancing tannin is one reason vintners blend different grapes.

Tannin is a natural preservative. Wines made to age can be rough, mouth-puckering, and bitter—even undrinkable—when young. Fortunately, time tames tannin. As years pass, tannins retreat to leave wonders in their wake.

Not all tannins are equal. Some are dry, rustic, harsh, chewy. Others supple, velvety, lush.

When you don’t like a red wine, villain usually is tannin. When you don’t like a white, culprit usually is acid.


• Norton Malbec. Mixed berry fruit, toasty finish. $9

• Santa Rita Cabernet Sauvignon Medalla Real. Muscular structure, dark, dense. $18

• White Oak Cabernet Sauvignon. Cherry, peppery, dense, rich. $29