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Old 03-18-2012, 02:27 AM   #1
johnp
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Jun 2010
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Instead of boiling and cooling some water (or using bottled water) can I use a half cup of my wort from the boil and cool it down to rehydrate my dry yeast? Or does the fact that it's sugary defeat the purpose of hydrating before pitching into a sugary wort?

I ask because I dont have any bottled water, and I'm about to boil some water for rehydrating, but I've got all this wort that's already boiling and it would be more convenient to just use that!

Plus if it is ok to just use wort, then why need I rehydrate? It would be the exact same as just dumping it into the carboy after its all boiled and cooled.

 
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Old 03-18-2012, 02:28 AM   #2
day_trippr
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Quote:
Originally Posted by johnp View Post
Instead of boiling and cooling some water (or using bottled water) can I use a half cup of my wort from the boil and cool it down to rehydrate my dry yeast? Or does the fact that it's sugary defeat the purpose of hydrating before pitching into a sugary wort?[...]
That's it in a nutshell...

Cheers!

 
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Old 03-18-2012, 02:29 AM   #3
johnp
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Lol I asked two questions in your quote. Is it ok? Or does it defeat the purpose?

 
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Old 03-18-2012, 02:33 AM   #4
bleme
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I was told that when the yeast is in it's dry form it's cell walls are semi-permeable. If you pitch directly, or use wort to rehydrate, a large potion of the yeast (I've been told half) will die. Once the yeast is rehydrated it's cell wall can protect it from the wort.

 
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Old 03-18-2012, 02:40 AM   #5
day_trippr
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Quote:
Originally Posted by johnp View Post
Lol I asked two questions in your quote. Is it ok? Or does it defeat the purpose?
Yes.

Ok, just playin'

As bleme mentioned, the cell walls of dried yeast can allow sugars to penetrate to the point that the yeast can literally explode. By gently hydrating the yeast the cell walls return to their desired condition where the yeast control the admission of wort.

Bottom line, if you're not going to hydrate with sterilized water, you'd be better off just sprinkling the dry yeast on top of your vessel of wort and let it sit there for 10 minutes before stirring...

Cheers!

 
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Old 03-18-2012, 03:01 AM   #6
johnp
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Perfect thanks dudes.

 
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