Possible Lager problem

[jerrylotto]

I brewed a Czech Pilsner and was fermenting it on Fermentis Saflager S23 yeast at 55° F. OG was 1.061 and it was down to 1.016 when my temperature controller went awry and the whole thing warmed up to 76°F. It was probably about an hour or two before I noticed and fixed the temperature probe, cooling it back down to 55°F over the next couple of hours. Now the following morning it's gravity seems to have stalled with the tilt reading 1.015. Did I ruin my batch, did I kill the yeast? Is it worth pitching another pack or just letting it go and lagering is normal? Does anyone have any experience that can tell me how this is going to (or could) impact the beer?

 

[dmtaylor]

It's not a problem at all. You might even want to keep the temperature elevated at this point anyway for a diacetyl rest. And it's probably done. In my experience, average attenuation of S-23 is 76%, and you are exactly right there. Leave it for another 4-5 days and if it's done, I'm not surprised in the slightest. And should taste as good as S-23 is able to. This is not my favorite lager yeast strain but some people love it.

 

[Dland]

I would let it go, but run at around 65F. Your gravity is right at the place where you would raise it up some anyway to clean up, D rest, etc for about a week. I very much doubt the temp rise killed the yeast

I see DM has similar advice.

 

[dmtaylor]

I see DM has similar advice.

Great minds.

 

[jerrylotto]

I raised it back up to 68F and I'm going to let it go for a couple of days. I'll tell everybody it was a purposeful diacetyl rest. Yeah - I MEANT to do that! ,

 

[Toxxyc]

I found S23 quite similar to S-189, but not quite as fruity. It's a fairly sweet finishing lager yeast though so give it the time it deserves and relax. I'm sure it's fine.