Blue cheese (or bleu cheese) is semi-soft cheese with a sharp, salty flavor. It is made with cultures of the edible mold Penicillium, giving it spots or veins throughout the cheese in shades of blue or green. It carries a distinct smell, either from the mold or from various specially cultivated bacteria such as Brevibacterium linens, which also causes foot odor and other human body odors. Some blue cheeses are injected with spores before the curds form, and others have spores mixed in with the curds after they form. Blue cheeses are typically aged in temperature-controlled environments such as caves. Blue cheese can be eaten by itself or can be spread, crumbled or melted into or over many other foods. History Blue cheese is believed to have been discovered by accident when cheeses were stored in caves with naturally controlled temperature and moisture levels which happened to be favorable environments for varieties of harmless mold. Analysis of paleofeces sampled in the salt mines of Hallstatt (Austria) showed that miners of the Hallstatt Period (800 to 400 BC) already consumed blue cheese and beer. According to legend, one of the first blue cheeses, Roquefort, was discovered when a young boy, eating 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 AD 879, though it is said that it did not 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 cheese originated subsequently, such as the 20th century Danablu and Cambozola, were an attempt to fill the demand for Roquefort-style cheeses. Production Similarly to other varieties of cheese, the process of making blue cheese consists of six standard steps. However, additional ingredients and processes are required to give this blue-veined cheese its particular properties. To begin with, the commercial scale production of blue cheese consists of two phases: the culturing of suitable spore-rich inocula and fermentation for maximum, typical flavor. Penicillium roqueforti inoculum In the first phase of production, a Penicillium roqueforti inoculum is prepared prior to the actual production of blue cheese. Multiple methods can be used to achieve this. However, all methods involve the use of