Have you ever noticed the instructions on the back of the yeast package differs from the kit instructions as to how to add the yeast to your wine must. Which one should you follow? The kit instructions are what we recommend.
The yeast instructions recommend hydrating your yeast. What does this mean? Hydrating the yeast involves dissolving the yeast in warm, not hot water, 40-43C before adding it you your wine must. Pretty specific, pretty narrow, huh!
Rehydrating the yeast, as the yeast companies suggest gives the highest live cells and the quickest, most thorough fermentation. But, if your temperature is outside of this range, problems arise. If the water isn’t warm enough the yeast’s cell walls won’t soften and the yeast won’t hydrate properly. If the water is too warm, the yeast will cook and die. And then you have to wait for the yeast to cool to within 2C of your wine must before adding it, as the temperature difference can be too much of a shock to the yeast and they will die. Pretty scary, huh!
So this is why we recommend simply dumping the yeast on the top of the wine must. While, it will undoubtedly result in a less live cell count than rehydrating, the survival rate is sufficiently high to properly ferment your wine. We think you will also agree it is a lot simpler that properly hydrating your yeast. Oh, and it is not recommended to stir the must after sprinkling the yeast.