Biotechnology of Wine Yeasts

Yeasts play a central role in the ancient process of winemaking. In spontaneous fermentations there is a progressive growth pattern of indigenous Saccharomyces and non-Saccharomyces yeasts, but the final stages are dominated by the alcohol-tolerant Saccharomyces cerevisiae. This unicellular “sugar fungus” is universally known as the wine yeast and is widely preferred for initiating wine fermentations. The primary role of wine yeast is to catalyze the rapid, complete and efficient conversion of grape sugars to ethanol, carbon dioxide and other minor, but important metabolites without the development of off-flavors. After several millennia of winemaking, researchers continue to seek full understanding of the scientific intricacies of the process through which grape juice is turned into wine, and how to perfect this yeast-driven fermentation for targeted consumer markets. Continuous improvement of yeast strains and blends of co-cultures is the corkscrew with which winemakers can open the bottled mystique of wine quality and consumer satisfaction. With every twist and turn, the underpinning biology of “single-species” and “multi-species” fermentations uncork novel ideas of how to improve the quality of wine, while minimizing resource inputs, production costs and environmental impact. Never before has there been so much opportunity to harness modern genomic and other technologies in strain development, and for winemakers to direct vinification to shape their wines according to the ever-evolving preferences of consumers.