With attribution to neither tool nor operator (though we all know which way the smart money goes), this morning I found my lagering freezer at 30F, well below the prior 35F set point. Somehow (see above) the controller’s brain got scrambled; it reported 100F set point and heating status, but the cooling relay was stuck on and the freezer was running.
Sometime between Tuesday evening and Thursday morning, my lagering WiesnGuy brew froze. Maybe not completely solid (the keg didn’t split and I did get a drop or two of liquid atop post when disconnected), but no flow on tap nor gurgle on shake.
HowToBrew mentions exactly this topic, but I may be near the seam of his recommendations:
“If you are towards the beginning of the lagering cycle, then there may not be enough yeast activity after it thaws to properly complete the attenuation and condition the beer. You should probably add new yeast. If you are at the end of the lagering cycle, and were planning on priming and bottle conditioning it, then you should probably add more yeast also. If you are planning on kegging it and force carbonating (like I was), then you don’t have to worry about it.” (my emphasis)
The beer was brewed Fri26Feb, fermented 50F to Thu10Mar, diacetyl rest 65F then racked to keg Sat12Mar to lager at 35F. OG was 1.052, racked at 1.012 very near FFT limit 1.010. Grain bill was 80% Pilsner, 20% dark Munich; about 25 IBU Hallertau. Yeast is WLP833, propagated second-generation reserved from prior starter.
This is a repeat of a favored brew that was frequently sampled (my very first lager!). IIRC (posting from office, notes at home) that brew was fairly OK after lagering 3 weeks but definitely better after 5-6 weeks and gelatin fining. I think most of the improvement was clarification and yeast “bite” reduction.
What should I do?
a) Should I let it thaw very slowly in kegerator space, or set it out to thaw more quickly? I doubt it matters, but ask while I’ve got your ear.
b) Is 1/5 lagering time reason enough to add more yeast, even though attenuation is essentially complete and I’m content to force-carbonate?
c) Should I add some pressure-canned wort to the fully-attenuated brew, to fuel surviving or added yeast?
Is (post-thaw) tasting likely to give information relevant to decide?
Either way, I’m gonna RDWHAB (alas, family party depleted inventory and RDWHAHB option). I really doubt it’s gonna be horrible whatever I do, I just want to minimize compromising a repeat of a brew I really liked.