Blue cheese mold would form. According to legend, Roquefort was discovered when a youth, eating a lunch of bread and ewes' milk cheese, abandoned his meal in a nearby cave after seeing a beautiful girl in the distance. When he returned months later, the mold ("Penicillium roqueforti") had transformed his cheese into Roquefort. Gorgonzola is one of the oldest known blue cheeses, having been created around 879 AD, though it is said that it did not actually contain blue veins until around the 11th century. Stilton is a relatively new addition becoming popular sometime in the early 1700s. Many varieties of blue
American cheese American cheese was often simply called "yellow cheese". Today’s American cheese is, by law, required to be manufactured from at least two types of cheese. Because its manufacturing process differs from "unprocessed" traditional cheeses, American cheese cannot be legally sold under the name (authentic) "cheese" in the US. Instead, federal laws mandate that it be labeled as "processed cheese" if simply made from combining more than one cheese, or "cheese food" if dairy ingredients such as cream, milk, skim milk, buttermilk, cheese whey, or albumin from cheese whey are added. As a result, sometimes even the "word" "cheese" is absent