Blue cheese contains an edible type of mold, which is where it gets its blue color. This makes it If any doubt remains, do not eat the blue cheese. It's better to. Aug 24, Blue cheeses are typically medium-hard, creamy cheeses injected with for one to two weeks after purchase as long as they are refrigerated. Blue cheese refers to cow's, goat's or sheep's milk cheese which has had a mold However, for blue cheese to last for this period of time, proper storage.