rehydrating yeast

Does anybody do this It was on the howtobrew.com web site:

"5. Rehydrate the dried yeast. Although many people skip this step with fair results, re-hydrating it assures the best results. While you are waiting for the brew water to boil, rehydrate two packets of dried ale yeast. Put 1 cup of warm (95-105°F, 35-40°C), preboiled water into your sanitized jar and stir in the yeast. Cover with plastic wrap and wait 15 minutes.



Next, "proof" the yeast. Start by adding one teaspoon of malt extract or table sugar to a small amount of water (1/4 cup, for example) and boil it to sanitize. (A microwave oven is good for this step.) Allow the sugar solution to cool and then add it to the yeast jar. Cover and place in a warm area out of direct sunlight. Check after 30 minutes, it should be exhibiting some signs of activity - some foaming and/or churning. If it just seems to sit on the bottom of the jar, then it is probably dead. Repeat the rehydration procedure with more yeast. (See Chapter 6 - Yeast, for more info.)"

I do the rehydration step, I've never bothered with the proofing part.

I would recommend it. It's easy enough to do while you are waiting for your pot to come to a boil. I know some people dont and just sprinkle the yeast on top, but this will get fermentation going faster.

I always rehydrate, but never proof. I follow the package directions on the yeast package, and sometimes that includes adding a bit of the cooled wort to it to help equalize temperature as to not shock the yeast.

From Danstar (makers of nottingham yeast):

Dr. Clayton Cone said:

Let me give you some facts regarding rehydration and you can decide for yourself where you want to compromise. Every strain of yeast has its own optimum rehydration temperature. All of them range between 95°F to 105°F. Most of them closer to 105°F. The dried yeast cell wall is fragile and it is the first few minutes (possibly seconds) of rehydration that the warm temperature is critical while it is reconstituting its cell wall structure.

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According to them, rehydrating at a lower temperature (such as room temperature), you can kill something like 20-30% of your yeast immediately, and pitching into wort at room temp is even worse than plain water.

For moderate-gravity batches I sometimes don't bother (usually when I simply forget), since even losing 20-30% or so, a dry yeast packet still has more than enough cells to be okay, but it's never a bad idea to do it just to be safe - and when doing something higher-gravity I ALWAYS rehydrate.

and Fermentis (Saf-ale, Saf-lager) has different instructions still.

I say, follow the manufacturer's instructions...they're the one that dried the yeast in their specific manner.

if its real generic/doesn't have instructions, rehydrate per the above...proofing is optional, although if its a really big beer, proofing will help wake up the yeast in a lower gravity, which means they'll do better in the thick gravity.

I almost always use dry yeast and my process is; pour about enough warm water in my carboy to just cover the bottom > sprinkle the yeast into the carboy and warm water > swirl it around to mix and let sit > come back once I flameout and swirl the yeast again > rack cooled wort onto yeast at the bottom of carboy > watch activity occur in about 4-6 hours
:rockin:

I'm a lazy slob. I just dump the yeast right in.

bradsul said:

I do the rehydration step, I've never bothered with the proofing part.

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Again, me too. It seems we follow the same procedures, lol.

I am a recent convert to rehydrating as my previous efforts resulted in killing more yeast than if I had pitched it as is. Reading the manufacturers instructions told me I was using water too hot. Since I've corrected this, I have had better results.

As I understand the issue, dried yeast membranes or cell walls or whatever you biology folks call the outer wall of the yeast cell, that part is not able to restrict what is allowed into the inner cell, so the wort hydrates the cell, not just water and so MANY of the cells die off. Rehydration is the way you get most of your dried out cells back up to snuff. I have heard that if you are too lazy to put your dry yeast in a bowl of water then you will need to use twice as much to get the same cell count working in your beer. I also have heard you should not stir the yeast but just let it float and rehydrate.

boo boo said:

Again, me too. It seems we follow the same procedures, lol...

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Must be a Canadian thing.