Had 8 bottles of cider explode in my fridge last night. Biggest mess I've ever seen. Glass EVERYWHERE. These were bottles that were cold-crashed a couple months back and put in the fridge. Well, now that the fridge has reached 20C with the resent IPA fermentation, I guess the yeast woke up and went to town on the remaining sugar. Result: BIG mess, no cider left.
Oh well, already got more apple concentrate. Next time I'll make it a low-enough gravity so I can let it ferment out.