I have a nice 15 l crock that came with a set of unglazed clay weights which continue to plague me as they develop mold every time between uses. I thoroughly sanitize (bleach soak) and dry them each time before and after use. I can only assume that since they are porous that the source of the mold is now deep within and isn't killed by sanitizing or drying. First question that comes to mind is why aren't these weights glazed to begin with to prevent the penetration of mold (spores?)? I've just removed the weights from my kiln where I fired them to 1000 deg. F for 1 hr. believing that will kill anything that is still a viable source of contamination. Don't know all that much about mold but guessed that 1000 deg. should do the trick.
thanks.... Gary