I saw this on Facebook but do it in the crockpot. It suggested putting the can in but I transferred it to a canning jar with lid so I could see if it had changed color and I wondered, too, if the can would bulge. The recipe online says 8 hrs on low in a crockpot but mine is older and it took longer. The instructions mentioned that the lid might seal but that does not make it safe for storing outside the refrigerator. Use for dipping apples!