How To Rehydrate Dry Yeast

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dgoldb1

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I've done some searching and have only found posts that say rehydrate in warm water for 20 minutes. How warm and is 20 minutes long enough? Does anyone use a stir plate to do this?

Any additional advice other than warm water for 20 minutes is appreciated.
 
My LHBS guy told me to boil 2 cups of water for about 10 min to sterilize it. Then wait for it to cool till about 90 degrees sprinkle the yeast on top, cover with saran wrap and leave it till your ready to pitch. I usually start it while I'm heating up my water for my specialty grains or mash water and its usually sits for about an hour with the yeast in before I'm ready to pitch but since I started doing it his way my fermentation has started a lot faster.
 
I've done some searching and have only found posts that say rehydrate in warm water for 20 minutes. How warm and is 20 minutes long enough? Does anyone use a stir plate to do this?

Any additional advice other than warm water for 20 minutes is appreciated.

What kind of yeast? What does the package say? If the package instructions aren't helpful try the manufacturer's website.

I've used Fermentis W 34/70 and S-23 and the instructions on the "product sheet" for rehydrating are very detailed.

I'd try googling the yeast strain you are using and I bet good instructions will come up.
 
Make a DME starter if you can. The instructions say rehydrate with water to keep things simple, but this doesn't guarantee maximum viability
 
Make a DME starter if you can. The instructions say rehydrate with water to keep things simple, but this doesn't guarantee maximum viability

This is not correct. The yeast will have maximum viability if you rehydrate in sterilized water before they are exposed to wort. This gives the yeast a chance to rebuild their cell walls before having to process the wort. You should not use distilled or RO water, as this water does not contain the nutrients needed for the yeast to properly rehydrate.
 
bergquistb said:
This is not correct. The yeast will have maximum viability if you rehydrate in sterilized water before they are exposed to wort. This gives the yeast a chance to rebuild their cell walls before having to process the wort. You should not use distilled or RO water, as this water does not contain the nutrients needed for the yeast to properly rehydrate.

Well why do people often sprinkle it right into the fermenter? Is that poor practice?
 
Well why do people often sprinkle it right into the fermenter? Is that poor practice?

According to Jamil's Yeast book, page 146:

Skipping rehydration of dry yeast kills about half of the yeast cells pitched... the dead cells immediately begin to break down and affect the beer flavor.


The yeast are vulnerable during the first few moments and are not able to regulate what passes through their cell membranes. Rehydrating with warm water before pitching reduces the shock they experience since warm water is less harmful to the yeast than sweet wort.

I've been sprinkling dry yeast onto my wort with good results but after reading the above I'm going to rehydrate the yeast in the future before pitching.
 
I wouldn't even sweat it for a stuck fermentation, just pitch it. I always get full attenuation with Notty by just pitching in anything under 1.060.

_
 
You might want to make a small "starter" with it, harvest some, and pitch it at the height of the krausen. If you put dry yeast right into the wort, they may not be able to survive in the alcoholic environment.
 
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