rehydrating dried yeast

[rcreveli]

I made Brandon O's Graff last night and decided to try rehydrating my us-05 before pitching. I left it in a 9" cake pan with warm water while cooling the wort and adding the apple juice and it seemed to take off much faster.

Anyone else rehydrating dried yeasts?

 

[7HockeyDad]

I rehydrate US-05 in about 12oz of water, boiled and cooled to 100F. I just use a large sanitized drinking glass, a sanitized table spoon, and sanitized thermometer. I boil the water earlier in my brewday in a teapot and just leave it on the stove to cool (I also use this water for rinsing anything I don't want iodophor on like my sanitized glass).

Here's my procedure:
-sanitize glass, thermometer, spoon
-rinse each a bit if you like (with pre-boiled water)
-fill glass part way and check temp (mine has usually cooled below 100F)
-heat water more and add if you let it cool too much
-at 100F, add yeast packet (after also sanitizing packet outside and scissors I open it with)
-let sit 5 minutes & cover with plastic wrap
-stir in yeast very well with sanitized spoon to mix it up good
-re-cover and let sit another 15 minutes
-Pitch it

 

[7HockeyDad]

I would be concerned about the large cake pan, even more so if you left it uncovered. I use the drinking glass with plastic wrap over it to prevent contamination. Maybe I'm way too cautious, but that beer is precious and I don't want to risk it.

My US-05 usually has good fermentation going after about 12 hours with wort at 70F.

 

[FromZwolle]

if you're going through the trouble of rehydrating, why not just do it a few days earlier and make a starter?
I've always pitched dry yeast dry, but i might do a starter with my upcoming batch.

 

[Beerrific]

if you're going through the trouble of rehydrating, why not just do it a few days earlier and make a starter?

Starters are not helpful when using dry yeast. The dry yeast manufacturers "lock" the yeast in a state where they have the highest metabolic reserves and are ready for beer. Putting in a starter will increase cell number but lose these reserves. When the yeast are dry and put into liquid they cannot regulate what can or cannot pass through their cell membrane. When you rehydrate in water you are going to end up just water in the cell, when you rehydrate with wort or just sprinkle you are going to get hops, sugar, etc in the cell. The yeast don't like this. I have seen reports that sate then when you just sprinkle you are cutting the viable yeast number in half.

Anyway, yes, I always re-hydrate. I just use a pyrex measuring cup so I can microwave to sanitize the water. Use 10 times the yeast's weight of water and let them stand for about 15 minutes. Stir then pitch. I also usually do not even start to prepare the dry yeast until my wort is in the fermenter.

 

[7HockeyDad]

I agree with Beerific. I read the same thing a couple other places as well about the locked in reserves that will be lost with a starter. No starters for dry yeast, but I did use two packets recently for a bit bigger beer (1.065SG) just to be safe.

For styles that work well with US-05, I am really happy with it. Of course I love SNPA so this yeast is my standby for my "House Brew".

 

[Homercidal]

I normally boil a bit of water in a flask and cool in a pot of icewater. Then pour into a sanitized glass and add yeast and after 15 minutes, swirl it up and pitch it.

Many people have good luck just pitching the packet directly into the fermenter, and I sometimes do that, but there are reasons why rehydrating makes sense and so I usually go through the trouble. Plus if it weren't better, I doubt the yeast makers would advise to do it.

 

[FromZwolle]

Starters are not helpful when using dry yeast. The dry yeast manufacturers "lock" the yeast in a state where they have the highest metabolic reserves and are ready for beer. Putting in a starter will increase cell number but lose these reserves. When the yeast are dry and put into liquid they cannot regulate what can or cannot pass through their cell membrane. When you rehydrate in water you are going to end up just water in the cell, when you rehydrate with wort or just sprinkle you are going to get hops, sugar, etc in the cell. The yeast don't like this. I have seen reports that sate then when you just sprinkle you are cutting the viable yeast number in half.

Anyway, yes, I always re-hydrate. I just use a pyrex measuring cup so I can microwave to sanitize the water. Use 10 times the yeast's weight of water and let them stand for about 15 minutes. Stir then pitch. I also usually do not even start to prepare the dry yeast until my wort is in the fermenter.

i stand corrected!

 

[rcreveli]

The reason I used the cake pan, sanitized and covered was from something I head on the Jamil show. During the mead episode the guest went to great lengths to gently rouse the dried yeast while maximizing the surface area for them to rehydrate. I figured if it worked for mead it would work for graff.

 

[nilo]

Starters are not helpful when using dry yeast. The dry yeast manufacturers "lock" the yeast in a state where they have the highest metabolic reserves and are ready for beer. Putting in a starter will increase cell number but lose these reserves. When the yeast are dry and put into liquid they cannot regulate what can or cannot pass through their cell membrane. When you rehydrate in water you are going to end up just water in the cell, when you rehydrate with wort or just sprinkle you are going to get hops, sugar, etc in the cell. The yeast don't like this. I have seen reports that sate then when you just sprinkle you are cutting the viable yeast number in half.

Anyway, yes, I always re-hydrate. I just use a pyrex measuring cup so I can microwave to sanitize the water. Use 10 times the yeast's weight of water and let them stand for about 15 minutes. Stir then pitch. I also usually do not even start to prepare the dry yeast until my wort is in the fermenter.

+1. Exactly the same procedure I do.
Just adding, re-hydrate with tap water (unfiltered), pre-boilled and cooled to 103 to 105F. And no, it is not too hot but the ideal temperature.

 

[kwaidonjin]

I re-hydrated my yeast for the first time for a stout and it was the first blow out I had. I am going to do this from now on.

 

[MirImage]

I re-hydrated my yeast for the first time for a stout and it was the first blow out I had. I am going to do this from now on.

I had this with the last beer I did too. 1st time rehydrating and I needed a blow off on day two. Will rehydrate more often. It was more amusing to watch than tv... I digress.

 

[kwaidonjin]

Fun to watch, not fun to clean up!

 

[ChshreCat]

My first few batches, I just sprinkled the yeast on top and they started and fermented just fine. The few after that, I rehydrated and they started and finished just as fine as sprinkling on top. Rehydrating isn't really much more work, so I still do it anyway. Anything to increase the odds of things not going wrong is good with me.