Hi wcaprar- contamination is always a possibility no matter what method of long term aging you use. You can get mould growth under you wax also, you have to get your wax temperature really hot(+200f) to ensure that you have killed any possible spores. Another possibility is using a Natomycin rub under your wax, not a method that we all embrace if you want an all natural product. The cheese wrap that you mentioned is used to store your cheese that has reached it's maturity and is ready to be consumed. The vacuum sealing will help in this problem but you can still get some spots, especially until the oxygen that is left in the bagged cheese is consumed by any remaining aerobic bacterial or mould activity.