What Yeast to Use?
The particular strain of yeast used in a fermentation will have some effect on the resulting wine. Many studies have been done on the effects of yeast - in many of these studies, the effects of different yeasts tend to fade after several years. Other factors - grape variety, degree of ripeness at harvest, sugar and acid levels, and yeast nutrient levels in the grapes, likely have a far greater impact on the quality of the final product.
Beginning wine-makers are encouraged to use one of the following widely-available and dependable yeasts:
Even experienced wine-makers are encouraged to consult with other club members before trying new yeast varieties. Many varieties of commercial yeast are developed to deal with specific problems or deficiencies in the grapes, and some have very high nutrient requirements. Yeasts with high nutrient requirements that find the nutrient levels in the must too low may throw yeast 'tantrums' - producing significant amounts of hydrogen sulfide (H2S), the rotten-egg odor. Over time this noxious chemical can react with other things in the wine to form other, also noxious smells that are even harder to eliminate. Hence, members are encouraged to consider having the nutrient levels of their fruit tested before fermentation, and to add nutrients several times during fermentation, when using a yeast with high nutrient requirements.
For those who are determined to explore other yeast strains, various yeast companies and other wine-related organizations have released recommendations related to the use of particular yeasts with particular fruits or grape varieties: