every batch I've made so far (5) has a sort of white or light colored film, on it. The bars have been coming out well and whatever it is i can lightly scrape it off with a credit card and it's fine after that. If any one can tell me what this is and how to avoid it I would greatly appreciate it. One of the soaps is water and the other 4 batches are milk based. The side that gets the film is the exposed side in the mold. Thanks