The only ingredients for Gorgonzola cheese are cow's milk, rennet and blue molds and salt during the aging process, when the cheese is washed repeatedly with brine.
The blue molds added to Gorgonzola are called Penicillium roqueforti. They form the typical blue veins of this cheese, and the longer it ages the more blue veins will develop. Their growth is stimulated by letting oxygen enter the cheese with the help of long needles which are inserted into the wheels of cheese.
Gorgonzola can be made with either both morning and evening milk or with one milk only.
The difference between Gorgonzola Dolce cheese and Gorgonzola Piccante cheese lies simply in the aging time. Sweet Gorgonzola ages between two and three months whereas Piquant Gorgonzola ages between three and twelve months. The former has a creamier texture and is used principally as a spreadable cheese and the latter is a semi-firm cheese which can easily be cut in slices and used to garnish salads.