Gorgonzola is a veined Italian blue cheese, made from unskimmed cow's milk. It can be buttery or firm, crumbly and quite salty, with a "bite" from its blue veining. During the aging process metal rods are quickly inserted and removed, creating air channels that allow the mold spores to grow into hyphae and cause the cheese's characteristic veining. Gorgonzola is typically aged for three to four months. The length of the aging process determines the consistency of the cheese, which gets firmer as it ripens. There are two varieties of Gorgonzola, which differ mainly in their age: Gorgonzola Dolce (also called Sweet Gorgonzola) and Gorgonzola Piccante (also called Gorgonzola Naturale, Gorgonzola Montagna, or Mountain Gorgonzola).