Lager - racked to secondary too early, now what?

[JSutt]

Hi, been lurking and sponging up info for a long time, but I can't find an answer to this question - sorry if it's been asked before!

I brewed up the Zatec Pils from Palmer's online book just over three weeks ago (May 30). I didn't record SG for whatever reason but it was within range - about 1.050 from memory. Target FG is 1.006-1.012.

I've been brewing for a few months but this was my first lager. Underpitched (1 pack of dry yeast) so fermentation was a bit slow to get going. Brought it up to 60f to start for a couple of days, then dropped it to around 50 and let it go.

Based on reading Palmer's book and a couple of online forums, I brought the temperature back up to 60f for a diacetyl rest (which I could taste as clear as day) for about 72 hours last week when the SG hit just under 1.020. On Saturday I racked it to a carboy and put it down in the basement in a tub of water to lager at ~45f for 4 weeks.

Ok, so the problem is that I (foolishly) forgot to measure the gravity before racking, as I was under the impression that fermentation would finish during the lagering stage. Obviously that is not correct, as I now realise. I took another measure this morning (just poured it out of the carboy - I know, tsk tsk) and the SG is 1.015. So yeah, it's not finished fermenting.

So what's the best course of action here? I know I've removed a lot of yeast from solution, but can I just warmed the carboy up again for a few days to finish it off? I've also rinsed and saved most of the yeast from primary fermentation. Would it be a good idea to pitch a cup or so of that? Or should I just leave it?

I'm using plastic PET bottles so I'm not worried about bottle bombs - I was wondering if I could just add a little yeast at bottling time but no sugar, and let the residual sugars in the beer do the carbing.

Any thoughts? Much appreciated in advance!

 

[Yooper]

For now, just bringing the temperature up should do the trick if it's still active. If the diacetyl is cleaned up, that's a good sign that fermentation is finished.

 

[JSutt]

Yes, the diacetyl has all disappeared, and boy does it taste good. So the only problem is likely to be a pilsner that is a little sweeter than it should be?

 

[madscientist451]

If its not finished, when you try to bottle carbonate, it may be over carbonated. You don't need to add any more yeast. Its best to run the fermentation out until its finished.
If it tastes good, finishing the last bit at ale temp shouldn't negatively affect the taste.
In fact this is the Tasty McDole quick lager method, ferment 48-50f until its more than half done then ramp it up 3 degrees a day until you get to 65, let it sit at 65 until its done, then ramp it down 5 degrees F every 12 hrs until you reach 32-30F. Let it sit at that temp a week then keg, of if you are bottle conditioning, let it reach room temp, bottle and condition then chill and drink, it should be ready. You can adapt this schedule to your specific equipment. Just keep the basic idea. When you racked to secondary you left behind some yeast and other things, but there should still be plenty of yeast in there to finish the fermentation and bottle condition.