Glossary entries

A reflection of yeast performance. Yeast converts sugar in grape juice into alcohol and CO2 during alcoholic fermentation. Under certain conditions, the yeast is unable to convert all the sugar. The amount of leftover, or residual, sugar in the wine determines its style. This is not to be confused with “sweet reserve,” which is unfermented (naturally sweet) grape juice left “in reserve” to add to finished wine (after fermentation) to fine-tune a wine’s style.