Rehydrating dried yeast is a quick and easy way of improving your beer if you are not already making a yeast starter. In fact, most dried yeast manufactures recommend that you re-hydrate yeast before pitching it. The primary benefit of re-hydrating your yeast as opposed to just sprinkling it on to your cooled wort is that, in their dried state, yeast cells are dormant; re-hydration awakens the yeast cells and prepares them so that they can begin fermenting the wort more quickly.
Additionally, re-hydration has an optimal temperature range to produce the highest number of viable healthy yeast cells. This temperature range is approximately 95F – 100F. If the temperature is much lower then that, which wort typically is in order to diminish the potential of hot side aeration and oxidization, yeast viability is greatly diminished. That means that if you do not re-hydrate, you are pitching far fewer active yeast cells and opening the possibility of a slower fermentation, a stalled fermentation, and potentially, an under fermented finished beer. In my mind, such an easy process should not be bypassed when you consider all of the effort that goes into making a quality home brewed beer.
Here are the quick and easy steps involved in rehydrating yeast:
1) Bring one cup of chlorine free tap water to a boil.
2) Cool the sanitized water and container to 95F – 100F. Make sure that it is not hotter than that or you may risk killing the yeast.
3) Gently sprinkle the yeast on top of the water, doing your best to avoid the sides of the container. Place tin foil over the top of the container to prevent anything from entering and contaminating the yeast; you will want to keep the yeast solution as sanitary as possible. Do not stir or swirl the yeast at this point; instead let the yeast become saturated by the water for 20 minutes. Wrap the container in a towel to keep the container warm and shield it from sunlight.
4) After 20 minutes, thoroughly stir and swirl the solution until the yeast has properly mixed with the water. Let the mixture stand for another 15 minutes or so, mixing it occasionally.
That is it; at this point you are ready to add your rehydrated yeast into your cooled wort. That easy process is how to re-hydrate yeast! Good luck and happy brewing.
How to Rehydrate Yeast