homebrewandbeer.com

I got a fridge on the cheap a few weeks ago, in which I've been brewing a pale ale, manually trying to keep it around 18 by running the fridge for a few minutes each morning and night. After 10 days or so in secondary, I figured I'd leave the fridge on to cold condition before bottling. Big mistake. Obviously the thermostat in this fridge is b0rk3d, because this morning my 20 L of beer was almost completely frozen!

How bad is it, guys? It should still be drinkable, right? But have I mangled the yeast to the point where it won't want to carbonate my bottles? It's Munton's Gold, if that makes any difference.

It will be fine.

Let it thaw.

Boil up some malt, water and a few hops (maybe 1/4 cup malt some cascade and 500ml water) , cool it down then mix it in to brew, just to wake the yeast up.
Leave for a few days to finish fermenting (use hydrometer) room temp.

Bottle.

Thanks Zuma, I'll give that a go.

My only concern with your suggestion is that there now no oxygen in the beer, it having completed fermenting. Will the yeast be able to ferment the extra wort I add? Or does O2 not matter at this stage, as the yeast will metabolise the extra sugars anaerobically? Or could/should I be able to aerate the additional wort without inviting infection and oxidisation?

I have never frozen my beer so I can't be 100% sure but this might be worth a read

http://www.howtobrew.com/section1/chapter10-6.html

Probably do as I suggested but cool the mini "wort" to 20c or so and pitch some yeast into it, mix well, prove and add to the fermenter.

Ah... I went ahead with your suggestion before reading your latest reply. I'd actually read that bit of How to Brew before - just didn't remember. I wonder if lager yeasts are more resistant to freezing than ale yeasts...

It didn't seem to be completely frozen right through, more kind of slushy. Yeast is pretty difficult to kill outright, isn't it? I'm hoping that worst case scenario is that the bottles will just take longer to carb, and I won't end up having to do something like uncap them all and add yeast.