Help! I once again attempted to make caramel apples, using this recipe, and this candy thermometer. But, tragically, the bottom layer of the sugar burnt, so there are oogy dark brown burnt bits in my caramel. I suspect it was something like I was using normal pans, not ones with extra thick copper bottoms. Or I had the heat too high? Has anyone else had this trouble? How did you successfully make caramel? Should I give up and buy some of that apple dip at the grocery store?