Is standard refrigerator temperature too cool to ferment a lager?

I brewed a Dortmunder Export yesterday and finally got it cooled down below 50F this morning in the fridge.  I split the batch and pitched half with WY 2124 and half with WLP 840.  We had to leave early this morning before I could get the keggerator emptied of kegs to re-configure for my lager ferment at 50F.  So, I just left the carboys in the fridge figuring I would transfer them over when we got back home.  Well I just got back home 12 hours after pitching and found both carboys bubbling away in the fridge at 40F.  So, should I ramp them up to 50F or just leave them alone at 40F?  It sure would be nice not to have to empty the keggerator out to use it as a fermentation chamber.

Get them warmer, or you run the risk of the yeast settling out before they finish attenuation. 45·F is about the lower limit for a lager. Or, if they’re most of the way through fermentation, you can bring them up to room temperature.

We keep our kitchen fridge at 46F and I ferment lagers in there (obviously small batches). It definitely takes a long time to ferment out but I get really clean fermentations.

I use a standard fridge to ferment my lagers. I tape the probe of my temp controller to the side of the carboy and then insulate it by taping bubble over it. Works well for me.

I think the question is in regards to doing it without a temp controller.

Ah… Well then I wasn’t much help then. ;0)

So I decided to move the lagers to the keezer at 50F.  I tried to set the fridge to the warmest setting but it still stayed at 41F.  I thought it would be warmer.  Interestingly, for the 2+ days that the carboys were in the fridge the one with the WLP 840 was going gang busters with significant (3 inch) krausen but the Wyeast 2124 was barely active.  Thanks for the input.

the 840 probably was a second generation with a really good count of healthy yeast.