I attempted to cold crash a couple batches yesterday (normally use the refrigerator, but ended up adding ice to a bucket and placing the one gallon carboy in there). Overnight, the ice melted and the temp got back into the low 60’s in the water. This morning I saw some small bubbles and was curious if this was yeast waking back up.
I’ve since stuck it in the refrigerator but I’m curious if I need to still ferment out for a while.
Bubbles could be CO2 coming out of solution as it warms. You’d have to check the gravity to know if it is that or new fermentation. Were you certain that fermentation was over?
You can’t manage what you don’t measure. Take a reading or maybe invest refractometer if you don’t want to sacrifice the volume for hydrometer readings in smaller batches. You won’t get accurate readings post fermentation with a refractometer but you can determine if the gravity continues to decrease or if it’s finished with just a few drops.
Well, at > 2 weeks it’s likely done. You can’t know for sure if you don’t take a reading, but I’m often lazy about FG readings with normal strength beers.