A cheese referred to as having a bloomy rind is referred to as such because of a very specific chemical reaction which happens during the cheese making process. Cheese makers use a process called mold-ripening. What is mold-ripening, you ask? Pretty much what it sounds like: The cheese maker will take a hunk of soft cheese and coat the outside of it with a particular strain of fungus (e.g. Penicillium candidum, which is used to make Brie and Camembert). These microorganisms form a rind that is characteristically soft and white by feeding on the cheese.