An astringent substance found in the seeds and stems of grapes, the bark of some trees and in tea. Tannin is important in the making of good red wines, aiding them in long and graceful aging. When such wines are young, the tannin often gives them a noticeable astringencya quality that diminishes as the wine ages, mellows and develops character.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.