Can cold water kill yeast?

[chaz56]

Hey guys I attempted to activate my yeast for the first time I read the packet it said to put yeast in 38-40 degree celsius but I didnt catch the celsius part till after so I put the yeast in 40 degree fareinheight is it possible that I could have killed the yeast?

 

[ErieShores]

Doubt it will kill it. I'm sure most LHBS keep theirs in a fridge and then sell them to you.

 

[lunchbox]

They might go dormant but they wont die.

 

[Gremlyn]

Thermal shock might kill some, but you will have enough left to get things going. Freezing the yeast cells in water would definitely kill them off, but just cold water won't.

 

[Pommy]

are you sure about the 38-40C bit? that's far too specific IMO, as long as its not ice cold water you will be fine. That is almost hot enough to kill most yeast. Room temperature is basically what you want but you will be fine. It is also advisable to let the yeast warm up by taking them out of the fridge before rehydrating, the idea is not to change the temperature too much, as memtioned above by Gremlyn, this will cause "thermal shock".

 

[chaz56]

Hey thanks guys the yeast didnt die i have a strong fermentation going on. Pommy ya the packet said 38-40C

 

[Justibone]

Thermal shock might kill some, but you will have enough left to get things going. Freezing the yeast cells in water would definitely kill them off, but just cold water won't.

When I made freeze concentrated bock (not very good, btw) there were a few yeast that survived the freeze. Not enough to carb the beer properly, but enough to make a CO2 "hiss" when I first opened the bottle after three weeks.

But you're correct, the vast, VAST majority of yeast in there kicked it. The bucket, that is. A tiny, tiny yeast-sized bucket.

 

[Pommy]

what yeast was it then just wondering? Sounds like it really wants to be pitched warm

 

[chaz56]

Mutsons yeast it was in a old truebrew kit I made