sweetness
sweetness is detected on the very tip of the tongue and, in wine, comes from residual sugar or, occasionally, from glycerol, a by-product of fermentation. The sugar may be intrinsic (from the grapes) or supplemental (as by adding grape concentrate) or both. Some fine sweet wines (such as Beerenauslese) are made from grapes that have been left on the vine until they’re so overripe that the fruit is sugar-laden and full of rich, concentrated flavors. The juice from such grapes contains more sugar than can be fermented out. Whether or not sweetness in a wine is pleasant or cloying depends on the balance between acidity and sugar. Though the term sweet generally applies to the sense of taste, certain components—such as oakiness, which contributes a sweet vanilla essence, or intense fruitiness—can give wine a seemingly sweet smell. See also sweet .
The New Wine Lovers Companion, 2nd Edition, by Ron Herbst and Sharon Tyler Herbst. Copyright © (1) 2003, 1995 by Ron Herbst and Sharon Tyler Herbst. Reprinted by arrangement with Barron's Educational Series, Inc.