Share 'Bottom coating problem'

Hi. We've been making chocolate-dipped graham crackers for awhile now, but we've recently run into a problem wherein the bottom coat separates after the entire cracker has been dipped. It doesn't happen immediately -- usually in a day or two -- and it only happens with the dark chocolate (Esprit des Alpes Garnet 63%). I've never come across this before and can't figure out why it's happening. As…