Can I kill the yeast during rehydration?

[jamesadunlap]

I am brewing my first batch, it is an irish stout kit that I got through midwest brewing supplies. I was multitasking when I shouldn't have been and put the dry yeast into water that was over 180 degrees. I quickly realized my mistake and cooled it back down by putting the container the yeast was in into a bowl of cold water. This happened about 24 hours ago, and although I know that it can take a couple of days for there to be noticeable fermenting going on, I was wondering if it was possible that I killed the yeast. If this is the case, can I add more or is the batch screwed?

[Stinkfist]

I doubt you killed them all but I am going to guess you killed a lot of them since basically anything over 126F will start to cook them...I would rehydrate another pack and pitch that...

[spiderwrangler]

+1 to stinkfist. You made yeastie soup.

[jamesadunlap]

Thanks. that's what I figured, but it is nice to get reassurance from people with experience.

[SacoDeToro]

I've found that dry yeasts can be rehydrated just fine at temps between 85-105 deg F. When I do use dry yeasts, I flash boil some water in an Erlenmeyer flask covered with foil. Once things have cooled to the point where I can comfortably rest the bottom of the flask on my bare forearm, then I know I'm close to 105 deg F. Think comfortable hot tub temps (103-105 deg F). I've never had a problem doing it that way.