Do white wines have tannins? How can you tell?

Dear Dr. Vinny,

Do white wines have tannins? How can you tell?

—Roger, Fort Worth, Texas

Dear Roger,

They do! Tannins occur naturally in grape skins, seeds and stems. They’re also present in the oak barrels used to age many wines, including some whites.

White wines, overall, have significantly less tannin than red wines. In reds, tannins provide that signature grippy feeling and the tug on the inside of your cheeks. In whites, tannins will typically contribute to a gentler feeling of structure that complements the wine’s acidity.

Some whites might also show what’s often called phenolic bitterness, which can be attributed to tannins and related molecules. Whites with more robust phenolic structure are likely to age well and may benefit from decanting.

Why do whites have so much less tannin? For starters, white wine grapes have less tannin to begin with. Plus, when white wines are made, it’s typical for the grapes to be gently pressed, and then just the juice is fermented. That means less exposure to the tannins present in the grapes. (Red wines, meanwhile, are typically made with more contact with the grape material, including extended maceration in some cases.)

Some white wines (plus rosés and orange wines) are made with some amount of skin contact. Those wines will have more tannins than whites made in the typical way, which involves minimal skin contact.

Finally, while there are plenty of white wines that are fermented or aged in oak barrels, it’s more common in red wines—especially the use of new oak. All that oak will intensify the tannin profile already present in red wines.

—Dr. Vinny