beer frozen during fermentation

A strange thing happened this weekend and I'm not sure what to do. I had a batch of pilsner fermenting in a chest freezer that had a digital temp controller hooked up and for some reason the temp probe failed causing the freezer to drop the temp and subsequently caused the batch of beer to freeze. I was frozen for 24 hours before I caught it and turned everything off. My question is whether or not that batch is ruined. The primary is basically complete but I would need to lager this for a few weeks yet. Not sure if I should throw this batch away or keep trying and see what happens. Any input would be welcomed!

It should be fine, you've started the lagering process. As I recall Palmer tells a story of his frozen lager in How to Brew.

I did something similar with a finished lager and froze the damn thing. I then unknowingly siphoned off my beer from keg to keg and left a large ice cube behind. Wound up with a highly concentrated drinkable beer.

You may need to pitch new yeast if the entire thing froze, but the beer should be fine.

Thanks for the quick responses. Is there a reason I should pitch new yeast? I've already completed primary fermentation and I'm kegging so don't need the active yeast for carbonation. If so I'll get some and pitch away but thought I'd see why I should do that.

No need for new yeast then. You had said primary was "basically" complete which lead me to believe you still had a couple points to go.

I had the same problem with my freezer. I switched to a fridge and haven't had a frozen batch. Now just use the freezer as the lagering chamber.

Same thing happened to me and my Pils. Thawed it out and it was fine and was a little stronger due to the ice distillation.