Penicillium glaucum. Albert Scheider / Bacteriological methods in food and drug laboratories, with an introduction to micro-analytical methods. 1915. / Penicillium glaucum in gorgonzola cheese. CostaPPPR / wikimedia / 2014 / CC BY-SA 4.0
Penicillium glaucum is one of two varieties of bacteria that is used to cause blue cheeses to develop blue mould.
It is used in making Gorgonzola cheese, and is used half and half with Penicillium roqueforti in making Stilton.
It is milder-tasting than Penicillium roqueforti.