Undercarbeb growler!
 

Sad days! 64 oz of liquid goodness is Under carbed :( oh well I learned my lesson to not try to carb in growlers

I've never carbed in a growler before so this may be worthless advice, but I have had carb problems before. I have found that almost 100 percent of the time, letting them sit a while longer in a slightly warmer area tends to do the trick. I would turn the bottles over - even kind of shake them a bit - every day or so. After another 1.5 - 2 weeks, they were great.

Confusious say:

Better to have under carbed beer than wet glass shards exploded all over room.

How long has it been in there? I notice it takes a bit longer to carb when conditioning in growlers.

AFAIK, most growlers are *NOT* designed to withstand the pressure of carbing beer. Do yourself a favor and get a tool designed for the job unless you are just itching to use your health insurance and enjoy glass shards. :D