Blue cheese of blue veins. The distinctive flavor and aroma of blue cheese arises from methyl ketones (including 2-pentanone, 2-heptanone, and 2-nonanone) which are a metabolic product of "Penicillium roqueforti". These compounds are not formed in other types of cheese fermented by bacterial acidification alone. In the European Union, many blue cheeses, such as Cabrales, Danablu, Gorgonzola, Roquefort and Blue Stilton, carry a protected designation of origin, meaning they can bear the name only if they have been made in a particular region. Similarly, individual countries have protections of their own such as France's Appellation d'Origine Contrôlée and Italy's Denominazione di Origine
Casín cheese Casín cheese Casín cheese ()is a Spanish cheese made in the Principality of Asturias. Its name is covered by a protected designation of origin (PDO). It is made from full-fat, unpasteurized cows' milk from specific breeds, namely Asturian Mountain ("Asturiana de la Montaña", a.k.a. Casina), Asturian Valley "(Asturiana de la Valles"), Friesian and any crosses between these breeds. Specifically the geographic area of manufacture is the southern part of Asturias which includes the Redes Natural Park ("Parque Natural de Rede"s) and associated land, this is within the municipalities of Caso, Sobrescobio and Piloña. The cheese is classified as hard and