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Old 06-19-2009, 07:02 AM   #1
K-Dub
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Hi all,

In doing my research it seems that most (including John Palmer) instruct to rehydrate the yeast, pour it into the fermenter and aerate and stir or shake. However, my kit instructions (which I know I should ignore) say to sprinkle the yeast packet on top, leave it and not to stir. I definitely want to stop using kits eventually but I'm taking baby steps and trying to learn as much as possible. Why the difference and which is the better method? Thanks.

 
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Old 06-19-2009, 07:27 AM   #2
NickBoz
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i am a beginner as well, i am only on my third batch and i slop it in, i splash around and sprinkle and my beers so far have came out good, but i may be wrong, also i always thought air was good for yeast.
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Old 06-19-2009, 09:54 AM   #3
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What people don't seem to realize is that sprinkling it on the surface of the wort and not stirring it for 15-30 minutes, is rehydrating, just on top of the wort as opposed to water. In fact on the fermentis website (safale/saflager yeasts) that is one of the iirc, 3 "recommended" options to do it...You stir (or I just rock the fermenter a bit-usually just carrying it from the kitchen to my brew closet) after the yeast has abosorbed the liquid....(reydrated)

all methods work, it really comes down to a matter of what works for you.
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Old 06-19-2009, 12:23 PM   #4
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I usually pour a bit of boiling water into a cup and then top it up with cold water till it becomes warm, then sprinkle the yeast on top and leave it for 30 minutes before adding it to the fermenter.

 
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Old 06-19-2009, 12:31 PM   #5
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If its just as easy for you to do both, I would say its better to rehydrate in H2O. Its an easier environment for the yeast to be dumped into.

 
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Old 06-19-2009, 12:39 PM   #6
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As per John Palmer, and Jamil Z. I now rehydrate my dry yeast every time. The purpose is to fill the cell walls with water before they start eating the sugars. If you rehydrate in the wort, then their cells could become filled with something other than water, which is not as good. My process is:

Little more than a cup of water boiled.
Let cool.
Add yeast on top let sit for 15 minutes
stir yeast into water
Let sit 15 minutes
Pour into cooled wort.

I spend that 30 minutes cleaning up stuff, or organizing notes (or would if I was any good at keeping notes...)
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Old 06-19-2009, 12:53 PM   #7
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+1 on rehydrating in H2O

Until a yeast cell's cell membrane is hydrated it cannot function properly. When that membrane is completely dehydrated, as in dry yeast, there is no control by the organism concerning what is being absorbed.

Pitching dry will kill yeast. Not all of them, but a quite a few are goners. Sure, dry yeast producers account for this by packaging more yeast than you need. But, why not give the wee beasties the best shot to get cranking, dominate the environment, and get to work.

A great analogy is, "I like scrambled eggs for breakfast. I just want to wake up before someone shoves them in my mouth."

 
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Old 06-19-2009, 01:03 PM   #8
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Quote:
Originally Posted by Edcculus View Post
If its just as easy for you to do both, I would say its better to rehydrate in H2O. Its an easier environment for the yeast to be dumped into.
I dunno, that premise always seems illogical to me....Since it is going to be eating wort, one would think that you would rehydrate it with the medium it is going to be eating.....Just like with a starters, you don't use sugar water but dme....It would seem that you would rehydrate it in the medium.

But like I said, it's apples and oranges, dehydrating, not dehydrating, dehydrating with water or on your wort, they all work.
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Old 06-19-2009, 01:20 PM   #9
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The yeast will ferment the wort whether their rehydrated or not. So the only issue is which method makes a better beer. Has anyone ever noticed any off-flavors that they can attribute to stressed out yeast from not rehydrating?

I don't normally rehydrate. I only do it if I'm repitching in to something with alcohol. Ordinarily I just sprinkle the yeast on top of the fermentor. I usually like to sprinkle it on the foam. I'm not saying my way is the best, but I haven't been convinced otherwise.

 
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Old 06-19-2009, 05:31 PM   #10
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I've always understood that rehydration in water gives you more viable cells from the package. Something about their ability to control what passes through the cell walls during the process. Other than what I've read (both here on HBT and at yeast mfgr websites) I have no way to prove that, and I always rehydrate so I have nothing to compare it to. But it makes me feel better and I'm happy with my beer.
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