Is my yeast still alive?

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emoutal

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Obviously, I won't know for sure, but I hope somebody can help me out.

First of all, the nearest LHBS to me is 1000 miles away, so going out and buying more yeast is out of the question. I normally get my supplies when I fly to Vancouver to visit. The last time I went, I bought supplies for two batches, both with Nottingham yeast.

Well I made my first batch last week, aerated as normal (carboy shake method), and pitched the yeast. I did not hydrate the yeast (I have done it this way before). 48 hours later, there was still no activity. I know that I should have waited longer, but I had an extra package of Windsor yeast, so I threw that in. Less than 12 hours later, it was going great.

Now a little background on the yeast. I bought it from a reputable store that keeps their yeast in a fridge. The problem came on my trip back home. I had it in my carry on, so it went through the x-ray machine (I have no idea if this would affect yeast). Then when I got home, it was really cold outside. -28C (about -20F). I tried to keep it out of the cold, but they spent maybe 10-15 minutes at that temp by the time I got my car started and warmed up.

Now the question I have is whether I should go ahead and brew my next batch? I have no backup yeast left. I will be going back to vancouver in two weeks and could buy more supplies, but I would love to brew before that. Should I risk it?
 

rsmith179

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Why not just get a starter going to see if the yeast are still active. Honestly, those cold temps would not have affected the yeast that much in that timeframe. As long as the starter gets going for you, you should have no problems with the yeast. At least it's not infected or anything like that...
 

Got Trub?

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Dry yeast should not be used to make a starter. The manufacturer has prepared those yeast in such a way they are at their optimum for pitching in terms of stored nutrients, cell wall etc. If you rehydrate you will ~ double the viability so that can help. There was some threads recently about the newer batches of Nottingham being much less vigourous then in the past.

GT
 

beesy

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i think you are cool. are you worried about the time it spent in the cold? I would not be. If you had it your pocket, your body heat kept them at a nominal temp. Dry yeast usually has 200-225 billion cells (2x more than a smack pack) so even if only half of them are viable, you are still in good shape. i say brew on!!
 

david_42

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Pitch the new batch on the cake or siphon some of the trub into the new fermenter, if you are in a big hurry.
 
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