Possibly Shocked/Killed my Yeast?

[naaate89]

Hello all,
I made a mistake when brewing a pilsner kit Sunday night and I'm not sure if I killed my yeast or if it's just dormant. I live in southern California and I usually hook my immersion chiller to the garden hose hookups outside. It was a really hot weekend so I wasn't able to chill the wort past 85 degrees using the immersion chiller, so I transferred the wort to my bucket, and put the bucket in my temp controlled refrigerator to get it down to pitching temp. I had the temp controller already set to the fermenting temp (54-55 degrees) and I was occasionally checking on it to see when it would get to around 70. The kit directions say to pitch at 60 but I usually pitch in the high 60's/low 70's and I had subbed out the dry yeast from the kit for some White Labs German Lager Yeast.

Anyway, I fell asleep on the couch waiting for it to drop to pitching temp. When I woke up at least 5 hours had gone by and when I ran out to the garage to check the fridge I noticed that it was already down to about 56 degrees. Instead of warming it up, I just pitched the yeast and added some nutrient right then. I forgot to aerate the wort and the yeast had been warming up to room temp for a few hours (probably 75 in the house). It's been more than 48 hours and I don't see any activity in the airlock. Did the 15-20ish degree difference kill it or cause it to go dormant? I figured it might be ok since it's at the ferment temp and the yeast could just be a slow starter. Any help would be appreciated! This is my first lager.

 

[VikeMan]

I doubt the temperature drop will be fatal, overall. It's not optimal, but probably not the end of the world.

Some guesswork... 5 gallon batch? OG around 1.050 or a bit higher? Single pack of Lager yeast and no oxygenation? I would expect a slow start and probably a longer than normal fermentation time.

 

[naaate89]

Yes 5 gallons, OG was 1.044 which is what the kit said it should be. I'm actually reading product info for my yeast and it says to pitch colder and let warm up naturally. I guess I made this more complicated by swapping it out. The white labs packet doesn't really come with any of this info about the yeast:

https://www.morebeer.com/products/wlp830-german-lager-white-labs-yeast.html

 

[VikeMan]

The lower gravity helps, but doesn't really change a lot, unfortunately. You might want to check out one of the yeast starter calculators to get an idea of how much yeast you should be using with ale and lager batches of various gravities. (And "always"oxygenate when using liquid yeast.)

 

[stamandster]

Not at all! I store all my lager and ale yeasts at 38f degree fridge. I have no issues with reviving them. They usually kick off very well once at a temperature that they reproduce at. Once you're at an optimal temp, you should be ok. Now, in regards to your lag, you might just have old/sluggish yeast out of the pack (expired?) or during transit to you they were exposed to a very, very warm environment that killed most or all of them. I've found, though, that lager yeast will not usually produce the same sort of krausen I see with many ale yeasts. Leave it for a week and check the gravity. If it's dead, pitch something else.