Castello cheeses remarkable popularity both in Denmark and abroad.” Castello was acquired by Arla Foods, who expanded Castello into cheese markets in North America. Castello blue cheeses were developed in the 1960s. The curds are dipped into salt water, drained, and put into molds. The cheese is punctured with tiny holes and then brought into the ripening room, where it stays for about 15 days. It is then washed, cut, packed, and put in a "cooling room" for about a week at a temperature close to freezing. The washed rind hosts various molds that add to the cheese's mildly spicy flavor. It
Blue cheese and the secondary fermenters, "Penicillium roqueforti", take over and break the lactic acid down, maintaining a pH in the aged cheese above 6.0. As the pH rises again from the loss of lactic acid, the enzymes in the molds responsible for lipolysis and proteolysis are more active and can continue to ferment the cheese because they are optimal at a pH of 6.0. "Penicillium roqueforti" creates the characteristic blue veins in blue cheese after the aged curds have been pierced, forming air tunnels in the cheese. When given oxygen, the mold is able to grow along the surface of the