I'm in need of a charlotte mold, and the ones I've seen for sale at my local cookware shop all have the same tinned coating that looks like it's about to peel off. Question for whomever makes charlottes here, what's the deal with this coating? Is it as fragile as it looks? I don't want it coming off in the dessert. And are all charlotte molds equal, or is there one or two brands that stand above the rest?