Uvaferm 43™: The tool to restart stuck fermentations. Uvaferm 43 was selected for its exceptional ability to restart stuck fermentations. Uvaferm 43 was chosen from among 33 different isolates that were tested against each other and also the traditional yeast typically used to restart stuck fermentations. The stuck fermentations used in the selection process were from wines with high alcohols (14.3% with 21 g/L RS) and high free SO2 (35 mg/L). Although it was selected for its ability as a ‘fix-it’ yeast, Uvaferm 43 also gives good sensory results when used in high sugar musts. It is classified as a Saccharomyces cerevisiae bayanus.