Rehydrating yeast and temp

[dmashl]

How important is having the rehydrated yeast slurry the same temp as the wort you are pitching into? Whats the +/- on the temp range? Tonight my slurry was about 7 degrees higher than the wort.

 

[kh54s10]

I have always read to rehydrate in 85 to 95 F. Then you pitch into wort that is cooled into the 60's.

I have always left my yeast at room temperature then pitched into cooled wort and have had no problems. I have also just done the sprinkle the yeast over the surface of the wort with good success. It is said this will kill 50% of the cells but the beer turned out great.

I don't think it is critical unless you are looking at an extreme in temperature differences.

 

[Brewmenn]

I'm sitting here wondering the exact same thing. I meant to start re-hydrating when I started cooling my wort and forgot.

 

[flars]

I've always used the information on the Fermentis site. Begin rehydration in water + or - 6°F of 80°F. Total length of time for rehydration is 30 minutes. Fermentis does not give information on what temperature the wort should be. My worts are usually 58° to 62°.

Fermentis does say the wort temperature should be at least 68° for rehydrating by direct sprinkling.

Other yeast manufacturers may have different instructions.

 

[brew_ny]

Fermentis does not give information on what temperature the wort should be. My worts are usually 58° to 62°.

after I rehydrate my dry yeast before I pitch I will add a couple of spoonful of wort slowly until the temperature of the yeast and wort are about the same

then pitch

all the best

S_M

 

[dmashl]

Brew ny, that sounds like a great idea. Adding wort to the yeast. I will try that next time.

 

[JuanMoore]

after I rehydrate my dry yeast before I pitch I will add a couple of spoonful of wort slowly until the temperature of the yeast and wort are about the same

then pitch

all the best

S_M

That's pretty much what I do, which is also what Lallemand/Danstar suggest in their rehydration instructions. They say that after letting the yeast rehydrate for 15-30 min, you should slowly add a volume of wort equal to the volume of yeast slurry over a 5 min period, and then pitch. According to Dr Clayton Cone of Lallemand, a sudden temperature change of greater than 15°F causes many of the cells to produce petite mutants, which can in turn create excessive H2S.

 

[flars]

Extra protection for a healthy ferment. Sounds good and easy to do.