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What To Consider When Selecting A Yeast


Joe Diaz — Windsor, California asks,

What is your decision-making process when choosing which strain of yeast to use?

Ah that is a wonderful and complex question. When a winemaker chooses to inoculate for fermentation (which I generally recommend) there are many factors to take into account when making that choice. To follow is a list in order of what I believe the importance of each factor to be. A complete article (or more) could be written on each of these parameters as each carries its own subtle effects. Many yeast suppliers have charts addressing many or most of these factors to help guide you, or visit • Suitability for varietal and application: Zinfandel yeasts typically need to be able to ferment higher potential alcohols under adverse nutrient conditions whereas a yeast to ferment a 21 °Brix delicate Riesling could be a completely different animal. To make high-Brix, high-residual sugar dessert wines, you’ll need a strong strain that produces low VA (volatile acidity). Always match your goals with your yeast. • Alcohol tolerance: This is my second most important criteria. As alcohol levels increase in a fermentation, the yeast cell walls become increasingly permeable and grow unable to