Castello cheeses cheese, named Noble Blue Cheese, Extra Danish Creamy Blue (also available sliced), Soft Blue, and Crumbled Blue Cheese. In 2012, the Denmark's Finest Havarti Cheeses were added to the Castello brand, followed by Saga Blue Brie in 2013. The Alps Selection Cheeses; Hirten, Bergkase, and Weissbier, were launched in the United States in the end of 2012, and were the first of their kind available in the United States. In some markets, the name Blue Castello is used for a triple-cream blue cow's milk cheese. Castello was established in 1893 by Rasmus Tholstrup of Denmark. His son, Henrik, bought a
Blue cheese enzyme, rennet, plays in removing the hairy layer in the casein micelle. Rennet is an enzyme that cleaves the κ-casein off the casein micelle, thus removing the strain that occurs when the hairy layer entangles. The casein micelles are then able to aggregate together when they collide with each other, forming the curds that can then be made into blue cheese. "Penicillium roqueforti" and "Penicillium glaucum" are both molds that require the presence of oxygen to grow. Therefore, initial fermentation of the cheese is done by lactic acid bacteria. The lactic acid bacteria, however, are killed by the low pH