Certified Specialist of Wine (CSW) Practice Exam

Residual sugar largely sets how a wine tastes in terms of sweetness, which is the main way we describe a wine’s style. When fermentation leaves little sugar, the wine comes across as dry; a small amount of left-over sugar gives off-dry; more sugar yields a sweet style. Because taste and perceived sweetness depend on acidity and alcohol as well, two wines with similar sugar can feel different, but the sugar remaining after fermentation is the primary driver of dryness versus sweetness.

How this is communicated on a bottle: producers and retailers typically describe the style with terms like dry, off-dry (semi-dry), or sweet rather than listing an exact sugar amount. You’ll see these descriptors on the label or in product notes, while exact grams per liter of residual sugar are not usually disclosed on everyday bottles (exceptions exist in some regions or for specialized wines).