Casu marzu is a type of sardinian pecorino
Pecorino is a cheese made from sheeps milk (sheep = pecora, hence pecorino), and in this case, the cheese is made of raw unpasturized milk. After the initial fermentation process that it undergoes just like any other type of cheese, the cheese fly Piophila casei lays it’s eggs in the natural cracks that form in the crust of some of the cheeses. A female P. casei can lay more than five hundred eggs at one time. The eggs hatch and the larvae begin to eat through the cheese. The acid from the maggots’ digestive system breaks down the cheese’s fats, making the texture of the cheese very soft; by the time it is ready for consumption, a typical casu marzu will contain thousands of these maggots.
This process of ‘rotting’ can be stimulated by drilling holes in the cheese on purpose.
Occasions and combinations
It’s usually eaten with pane carasau, the traditional bread of the Barbagia area and an abundant glass of red cannonau.
I tastes like a spicy cheese, Andrew Zimmern described the taste of the cheese as “so ammoniated” that “it scorches your tongue a bit.” Andrew Zimmern of Bizzare foods dedicated part of a documentary to it.