How Blue Cheese Is Made and Why Is It Blue?
Blue cheeses are all made from cow’s milk except from the famous French Roquefort cheese, which comes from ewes’ milk. The blue in blue cheeses is essentially blue mould. But it is extremely good for you. What happens is that an organism similar to penicillin is added to the milk or curd used to make ordinary white cheese. The mold, during three to six months of ripening, grows either in small, irregular natural openings in the cheese or in machine-made perforations, depending upon the type of cheese.
The small amounts of mold reproduce or spread to give the typical blue streaks in the white cheese, and, once ripened, the distinctive flavor. Blue cheeses are usually heavily salted to add to the flavor. The smell of this food is due both to the mold and to types of bacteria encouraged to grow on the cheese: for example, the bacterium Brevibacterium linens is responsible for the smell of many blue cheeses, as well as foot odor and other human body odors.
Blue cheese is a general classification of cheeses that have had cultures of the mold Penicillium added so that the final product is spotted or veined throughout with blue, or blue-grey mold and carries a distinct smell, either from that or various specially cultivated bacteria. 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 a temperature-controlled environment such as a cave. Blue cheese can be eaten by itself or can be spread, crumbled or melted into or over foods.
Blue cheese is believed to have been discovered by accident when cheeses were stored in natural temperatures and moisture-controlled caves, which happened to be favorable environments for many varieties of harmless mold. It was moist in the cave so the 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.
It is often claimed Roquefort was praised by Pliny the Elder in AD 79. However, in the text, Pliny speaks of a cheese from Gaul, without mention of origin or even specifying that it was blue. This story was promoted by the ‘Société des Caves. Today this natural mold is refined and used for almost all blue cheeses. The mold culture is simply added to the cheese milk. For the cheese to turn blue, oxygen must be inserted into the cheese through thin needles or skewers. The blue mold then matures inside the air tunnels, developing flavour as it ages. Most mold cheeses take three to six months to mature. In blue cheese, this happens uniquely from the inside outward.
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. To fill the demand for Roquefort-style cheeses that were prohibitive due to either cost or politics, many varieties of blue cheese originated subsequently, such as the 20th century Danabluand Cambozola.