A five-ounce glass of red table wine or chardonnay contains around 0.9 grams of sugar. Dessert wines, on the other hand, are sweeter and are usually served in smaller glasses. The sugar in these drinks may be added by the wine maker or comes from naturally occurring sugar in grapes. A single glass of dessert wine can contain as much as 7 grams of sugar. Dessert wines are often served as aperitifs to accompany a variety of sweet dishes and can brighten up the after-dinner experience.