There are plenty of reasons why you might not want to try casu marzu cheese. First of all, it’s crawling with squirmy maggots—the wormlike larvae of flies. Secondly, eating it could make you ill. Lastly, it’s illegal to produce, sell, or purchase!
Casu marzu is a sheep’s milk cheese from the Italian island of Sardinia. It’s created by poking holes in or removing the outer rind of a wheel of hardened pecorino cheese. This allows cheese skipper flies (Piophila casei) to burrow into the wheel and lay their eggs. The larvae hatch and feast on the cheese by secreting digestive enzymes that break down its fats and proteins. Over time, this turns the cheese into a smelly, oozing goo with an intense, tangy flavor.
Casu marzu means “rotten cheese” in Sardinian. It is traditionally eaten on bread—wriggling maggots and all! Sometimes the insects even jump out of the cheese onto the faces of the people eating it. Consuming this cheese comes with serious health risks. “The live maggots could carry bacteria your body doesn’t like,” says Michael Tunick, a food scientist at Drexel University in Pennsylvania. Ingesting harmful pathogens can be dangerous. Some cause vomiting, diarrhea, and stomach pain. And if larvae from casu marzu were to survive their trip through the digestive tract, they could end up gnawing on people’s intestines, causing internal lesions.
Despite being a traditional delicacy in Sardinia, Italian law prohibits the sale of food infested with parasites, like casu marzu. Anyone caught selling it faces fines up to $56,000. Still, some Sardinians continue to make, sell, and eat this controversial cheese.