Primary Lager Temps

I know that primary ale fermentation increases wort temps by 5 degrees or so, does this apply to lagers as well? Reason I ask is that I can't get my fridge up to sustain 50-55 degrees, my basement is too warm at 65 and my basement bulkhead is too cold at 46-48. I'm thinking that the bulkhead may be OK if the wort runs 5 degrees warmer, albeit on the low side of the fermentation temp range (WLP820 @ 52-58). Any thoughts? Should I throw it in a water bath with frozen water bottles instead?

I think the basement bulkhead is going to be your best bet.

Thanks, thats what I figured but am concerned that night temps may get too low (I may have to pull it back into my basement near the door until morning). So will wort temps be 5 degrees or so higher during fermentation from heat generated? This is for primary, after a D-rest I'll put it i the fridge at 32-34 for 4-6 weeks...

Can anyone confirm if primary lager fermentation runs slightly higher than ambient air temps much like ales do? What are the chances of WLP820 konking out if temps get down to 46-48 (White Labs suggest 52-58)?

I would imagine that all fermentations run slightly higher than ambient air temps. I would also guess that with a lager it is not as much as an ale. I am 24 hours in on my first lager and can tell you that the freezer the carboy is in "seems" to be warming up freezer up faster than it would warm up without the carboy. It is hard to tell for sure because A) I don't sit and watch it for long periods and B) I took about 3 gallons of bottles out and put in 5.25 gallons of wort. So the conditions changed, but it should be a little more stable in there with a 5.25 gal thermal mass compared to 3 gallons or so yet the thing seems to kick on more often.

My 2-day old Okterberfest is in the primary in my basement bulkhead. Temps in there have been 43-50, well below the 52-58 recommended by White Labs for WLP820, but its chugging away pretty steadily. I can help but wonder what kind of effect the lower temps will have on it...I was going to pull it into my basement overnight and put back in the bulkhead in the am, but figured the changes in temps may be worse than just leaving it colder than recommended.

I don't know...guess its time to RDWADMCTM (relax don't worry and drink my coffee this morning).

Whether it's right or not, the general rule i go by is that at the height of fermentation (regardless if it's an ale or lager) add 5F to ambient temp. If it's a more vigorous/violent ferment than "normal", it's probably fermenting 5-10F warmer than ambient - i'm thinking Belgian & Wheat strains, specifically.

The temperatures listed by the yeast companies are "optimal". Most lager yeasts will ferment well into the 40s°F, some as low as 42°F. The lower you go. the slower it will ferment, but it will still ferment and will be a very clean lager. The only catch is to start at that temp. If you start at say 60°F and then try to continue fermentation at, say, 45°F, it might crash.

Most refrigerators will stay as warm or warmer than 45°F at their warmest setting. If you have the spare fridge (without a temp. controller), I'd ferment it in there at a warm setting and keep an eye on the temperature. If it stays around 45°F, actual fermentation temperature at high krausen should be close to 50°F.