Blue cheese is semi-soft cheese with a sharp, salty flavor. It is made with cultures of the edible mold Penicillium, giving it spots or veins throughout the cheese in shades of blue or green. It carries a distinct smell, either from the mold or from various specially cultivated bacteria such as Brevibacterium linens, which also causes foot odor and other human body odors.
Some blue cheeses are injected with spores before the curds form, and others have spores mixed in with the curds after they form. Blue cheeses are typically aged in temperature-controlled environments such as caves.(citation needed)
Blue cheese can be eaten by itself or can be spread, crumbled or melted into or over many other foods.