Which is better for smoothing out red wine tannins, decanting or bottle aging?

Dear Dr. Vinny,

Is it fair to say that the higher the tannins, the greater the need for bottle aging (to smooth out the tannins)? Can decanting be substituted for age?

—Tom, Fla.

Dear Tom,

While I understand your logic, I would emphasize that not all tannic wines will taste better after aging. Many wines built for aging happen to be tannic, but remember that a wine cellar is not a wine hospital, and everything depends on the quality and ageability of the wine you start with.

You can’t put a wine with astringent, raw tannins in a cellar and expect an elegant, smooth wine to come out on the other side. A wine needs other elements—especially concentration and balance—to age well. I’ve had plenty of aged, tannic wines that never resolved in the cellar, and plenty of wines I’d never describe as tannic that were gorgeously aged.

Can a tannic wine benefit from decanting? Yes, many wines will become more expressive and aromatic with decanting, especially younger wines. In many cases, oxygen exposure can make the tannins seem rounder and softer—though it’s not going to make a young wine’s tannins feel resolved in the way that aging can.

Remember that as a wine ages, phenolic compounds link together to form polymers, some of which drop out of suspension to form sediment. Those long-chain tannins are responsible for the velvety mouthfeel that makes aged wine so special. But decanting only integrates oxygen into a wine—the short-chain tannins are still going to be pronounced. Simply put, decanting cannot replicate the effects of aging.

—Dr. Vinny