Wines get their sweetness from residual sugar (RS), leftover glucose from grape juice that wasn’t wholly fermented into alcohol. However, our sense of taste picks up sweetness at varying levels.
Most still wines fall into the dry category, even though our taste buds might tell us differently. There also “off-dry” wines, that are included in this section. “Off-dry” is a popular term to describe wines with a touch of residual sugar, which can be anywhere from 2–3 grams of residual sugar per 5 oz pour. Most off dry wines are white wines, although on rare occasions you can find high quality Italian red wines that fall into the off dry category. High acidity wines like Riesling will taste more dry than a lower acidity wine (like Viognier) at the same actual sweetness level.