Fridge stopped for a day on my Primary Lager Ferm

[Brewmancer]

Hi Everyone!

I've been reading and listening for awhile now and want to thank everyone for all the superior information! My brewing skills have increased dramatically since I found the fountain of knowledge here on The BN.

I did finally hit a possible snag that I haven't seen any previous mention of that I would love some feedback on.

I brewed a Baltic Porter (very) loosely based on JZ's "Zek's Porter" in "Brewing Classic Styles" on 4/16/10. Target OG was 1.076 and I came in at 1.074 so was happy with that. Cooled my Wort down to 62 and pitched (my Shirron Plate Chiller and my hose only get me about 60-64 so I forgo the Narziss Ferm and just use a D-Rest). I'm re-pitching WLP833 German Bock Lager from a 1.055 Munich Dunkel. Immediately after 2 minute aeration and pitch I place the Carboy in my fridge that is set at 48F.

After about a 6-8hr lag time I have a nice healthy Krausen and good fermentation activity. I give it about 3 days of high Krausen with sanitized tin foil on top before I switch to a good ol' Air Lock. Still have great fermentation signs, bubbles, movement, steady 50F Wort temp and everything is going swimmingly....

Last night, 4/21 around midnight is my guess; my fridge popped a breaker and went out. I check in on my lovely about 9am and see my temp is up to 62-63F with crazy Air Lock activity! I immediately switched to another circuit and fired the fridge back up. After I got home from work (7pm) it was back down to a steady 50F but with no Air Lock activity. I still have a healthy Krausen and some movement in there but I'm scared I've shocked my poor little yeasties too badly.

Anyone have any ideas on what I have or haven't done to my beer? I haven't taken any readings yet (playing the hold my breath and see game) so no idea how much attenuation I have so far.

Did I do the right thing turning the fridge back on or should I have taken it as a pre-mature D-Rest? (I generally primary for 3 weeks before 3 day D-Rest at 66-68F) Did I cool everything back down to quickly? Should I have left it there or shot for a mid-point? You get the idea.

Any help/feedback or suggestions would be awesome!

Thanks in advance!



-J

[Quin]

The fermentation definitely slowed down and maybe stopped. At 62°F the beer wont hold as much CO2 as at 48°F, so part of the activity was CO2 coming out of solution. Now back at 50F, it will hold more than at 62F, so it will take a while for it to reach saturation. You'll have to take a gravity reading to see where you are. It may be through.

In the future, I wouldn't drop the temp so fast. Either leave it at 62 or drop it 2° a day back down to your ferment temp.

[Brewmancer]

Thanks for the feedback mate. It went against my gut crashing the temp back down like that but I was running late for work and in panic mode so my brain kind of shut off there for a bit. Ah well, Brew and Learn!

I'm gonna take a reading tomorrow when I've got everything out to keg my APA and I guess go from there.

Cheers!

-J

[BDawg]

One thing that might help ease your mind is that most of the ester formation is done in the early stages of fermentation. This one had been going for 3 days with a full krausen. You could think of it as an early diacetyl rest.

I agree that it would have been better to drop it 1 or 2 degrees at a time. But, what's done is done.
Keep your eye on it, and give it a taste when all signs of activity stop. If the cooling caused a partial vaccuum to form, that should be gone by now and you should have new airlock activity.
If not, then I'd rouse the yeast raise the temp to get it restarted, and relower it on the slower schedule. (Maybe pitch a pack of SafLager)?

HTH-

[Brewmancer]

Well I checked my gravity today and it's sitting at 1.026. Not as low as I was shooting for but it doesn't appear to be finished yet. I do have some slow air lock activity going and my Krausen doesn't show any diminishment.

I'm going to give her a little swirl and just sit back for a bit. I'll check it again tomorrow and start raising the temp if need be. I did give it a taste today and was all in all fairly pleased. No noticable esters and pretty close to what I was shooting for. Still a bit too full bodied and "cloying-ish" but if I can hit 2-4 more points I'll call it a win.

-J

[Brewmancer]

Ahhh sweet miracle of pitching enough healthy yeast, those little bad boys are still kicking. Checked today and sitting at 1.022 with noticable activity still going and it tasted pretty awesome to boot.

I love still making good beer when you think you've possibly screwed it up

-J