Originally Posted by Brewnoob1
If you were fermenting in the 50s, then it was a slow moving fermentation and that is why it stalled out (airlock isn't a good indication of fermentation by the way). Ale yeast thrive (taste and quality wise in the mid 60s) 50s...you're talking lager yeast should have been used. As with everyone else...I think it wasn't quite finished but was down enough to not have bombs. Just chill for a longer and drink em up. Chalk it up as lesson learned and move on to brewing more beer
Ale yeasts often that can handle the 50s, but it's generally well below their optimal range.
I use a similar method to control my temperatures. I get my water bath as cold as possible to start, because it's easier to have it warm up than cool down once things kick off.
I just started another batch Sunday. Water bath was at 40 to start, which is about normal for me since it's full of ice... but I also use that to help me get my wort temp down, my immersion chiller gets it to 80 in about 20min, and I can get it to 70 from there, but it'll be a long time... so I prefer just to get it in the carboy or bucket and then stick it in the ice bath to cool down the rest of the way.
But by the next morning it's usually up to 56-58. Once I hit that temp range I rotate frozen bottles twice a day and it keeps the water around 58-60 and I haven't had my beer get above 66. Once active fermentation is finished I'll wait a few days, then stop putting in the ice bottles and the temp creeps up to 70. After a few more days I'll take it out of the water bath and it'll climb up another few degrees, normally to 74-75ish.
If you're keeping your beer in the 50s by switching in your frozen bottles twice a day, try bringing it down to once a day and see what happens. I found I was able to dial in my process really quickly by keeping a close eye on things the first few times, and since then it's gone really, really well. I still want to build a fermentation chamber though, heh.