Allegro Yeast Allegro is a H2S-preventing yeast strain selected for white wine fermentations. It is well suited for aromatic expression of any white varietal and is capable of delivering soft mouth feel characteristics. Allegro is exceptional at focusing the fruit – either alone or as part of a blend – and is an excellent choice for Chardonnay and Sauvignon Blanc. Renaissance Yeast’s strains have excellent fermentation kinetics, desirable sensory characteristics, and are produced to the highest quality standards. Renaissance Yeast is the exclusive developer of a novel, patented H2S-preventing technology that is the result of a natural trait in yeast that increases sulfur and nitrogen utilization efficiency during fermentation, thereby preventing hydrogen sulfide formation.