Blue

What is Blue Cheese?

Blue cheese was probably found by accident, in caves where the steady temperature and moisture happened to suit harmless molds. Paleofeces from the salt mines of Hallstatt in Austria show that miners of the Hallstatt Period, 800 to 400 BC, were already eating blue cheese and drinking beer. Legend gives Roquefort a more romantic start: a boy eating bread and ewes' milk cheese left his meal in a cave after spotting a girl in the distance, and months later Penicillium roqueforti had turned the cheese blue.

Gorgonzola is one of the oldest known blue cheeses, created around AD 879, though it is said to have had no blue veins until about the 11th century. Stilton is newer, becoming popular in the early 1700s. Danablu and Cambozola both arrived in the 20th century as answers to the demand for Roquefort-style cheese.

Production starts with raw milk from cattle, goats or sheep, pasteurized at 72 C (162 F) for 15 seconds. A starter culture such as Streptococcus lactis turns lactose into lactic acid, then rennet coagulates the milk. The curds are cut with a knife to release whey, and the smaller the cut, the harder the finished cheese. Once ladled into containers, the curds get a sprinkling of Penicillium roqueforti inoculum along with Brevibacterium linens, then knit into loaves with a fairly open texture. Whey drains for 10 to 48 hours under no pressure, with frequent inverting, and brine or dry salting runs 24 to 48 hours.

Fresh blue cheese has almost no blue cheese flavor. That takes a fermentation period of 60 to 90 days, usually at around 8 to 10 degrees Celsius and 85 to 95 percent relative humidity. Early in ripening the loaves are punctured so air can reach the aerobic Penicillium roqueforti and the veins can form. The characteristic smell and taste come from methyl ketones such as 2-pentanone, 2-heptanone and 2-nonanone, metabolic products of the mold, and from the breakdown of fat.

Color runs from pale to dark, consistency from liquid to hard. Some blue cheeses smell distinctly of the mold or of cultivated bacteria like Brevibacterium linens, the same organism behind foot and body odor. Gorgonzola, Stilton and Roquefort are the favorites in many countries, and each carries a protected designation of origin, so the name depends on both region and method. Cabrales and Danablu are protected too. Cheese made outside those rules is labeled simply blue cheese.