Describing cheese ripened with blue molds, typically Penicillium roqueforti or Penicillium glaucum, whose growth through the paste creates the characteristic blue-green veins and marbled appearance. Cheesemakers pierce the young wheels with needles, admitting the oxygen the mold needs to bloom along the channels, then age the cheese in cool, humid cellars while enzymes break down proteins and fats into the sharp, peppery, complex flavors blue cheese lovers prize. Roquefort, Stilton, Gorgonzola, and Danish blue each express the style differently, from crumbly and fierce to creamy and mild. The mold is entirely safe and intentional, a delicious demonstration that in cheesemaking, the right microbe at the right time is the difference between spoilage and sublime.