Penicillium roqueforti sketch and photo of in cheese. Charles Thom (1872-1956) / Fungi in cheese ripening : Camembert and Roquefort. – Washington, 1906. – P. 35. Fig. 2. Public Domain. Nobtis / Getty Images via Canva Pro
Penicillium roqueforti is one of two varieties of bacteria that is added to blue cheeses to cause it to develop the characteristic blue mould.
It is used in cheeses such as Roquefort Cheese and Maytag Blue Cheese, and is used half and half with Penicillium glaucum in making Stilton.
It is stronger-tasting than Penicillium glaucum.