Would You Eat Casu Marzu, the Illegal Cheese With Maggots?

By: Alia Hoyt & Lauren David  | 
Casu marzu
Casu marzu cheese has live maggots and has been a part of the Sardinian food culture for centuries. Gengis90/Shutterstock

Maggots with your cheese, anyone? The thought alone may make you squeamish but before you start forming opinions, maggot-filled cheese really does exist and it's considered a delicacy on the Italian island of Sardinia.

It's called casu marzu, which in Sardinian means "rotten cheese," so its name isn't too off. It's reputed to have a strong smell and acidic and pungent taste. For a cheese that is only available in a small region in Italy — and one that's illegal, to boot — casu marzu has managed to become quite well-known in the United States. Food personalities, such as Andrew Zimmern and Gordon Ramsay, have likely helped shine the spotlight on the cheese both in the U.S. and on social media.


What Is Casu Marzu?

Casu marzu, as we said, is a cheese made only on the island of Sardinia. The cheese starts out as a typical pecorino and when aged, cracks form, allowing for a special ingredient to enter the wheel — cheese skipper flies (Piophila casei).

"While it ages in the open air, the cheese naturally dries out and cracks, which allows for a particular type of 'cheese fly' to climb in and lay eggs," Julia Birnbaum, cheese expert and founder of Philly Cheese School says via email. When the eggs hatch, maggots squirm and wiggle in the cheese. As the larvae eat and digest the milk proteins, they break down the acids of the cheese and make the texture soft and creamy. One wheel can host thousands of maggots.


Typically, after about three months, the cheese is ready to eat. It becomes gooey and a liquid — known as lagrima or tears — oozes from the rind.

"Casu marzu is made around June and July when mama sheep are chomping on nutrient dense summer grasses, just like pecorino, Romano and many other sheep's milk cheeses," Birnbaum says. "This imparts the milk with more complex flavors, which only strengthen after a few months of aging."

Casu marzu
Many people compare casu marzu's taste to an intense gorgonzola, with a remarkably creamy and oozy texture.


Why Is It Illegal?

Casu marzu is illegal in the United States and throughout Europe, including Italy. Yes, that's right, it's banned in the country where it originates. The cheese has been illegal to sell in Italy since 1962, due to a food safety law regarding eating food with insects and parasites. Then in 2002, EU regulators made things worse. A European food safety law was passed making sales, importation and production of casu marzu illegal throughout all of the European Union. The Sardinians applied to get a Protected Designation of Origin for casu marzu after the ban, but were denied.

But people continue to make the cheese in Sardinia despite it being illegal to sell. It's mostly small farmers who make it, so you won't find casu marzu at cheese shops in Sardinia, as cheese makers don't want to risk hefty fines.


Visitors to Sardinia with a desire to sample this cheese usually find a way to get their hands and their taste buds on some casu marzu. "Just like other products with legal restrictions, rumor has it that casu marzu is attainable through a 'black market' where sellers risk heavy fines if caught by authorities," Birnbaum says.

History of Casu Marzu

Like many cultural foods, it's believed this unique cheese happened by chance. After all, it's hard to imagine someone deliberately putting fly larvae in their cheese without having some idea that it could make the cheese better.

Although today some cheese makers do add the larvae into the wheels for the magic to happen, others put their cheese in the hands of nature.


Despite being dubbed the "world's most dangerous cheese" by Guinness World Records in 2009, so far there is no record of anyone dying from eating any. But food scientists have proven that flies can spread bacteria that can cause food poisoning, including salmonella. And those maggots? Well, they aren't healthy either. As they do their thing in the cheese, they can create cadaverine and putrescine — compounds produced when amino acids decompose in decaying animals that can be toxic in high doses.

But Sardinians have been eating this culinary delicacy for centuries — and they still eat tons of it. For those brave enough to bite this creamy goodness with living maggots squirming around, there's a bigger concern about what can happen afterward. There can be health consequences if you don't properly chew the maggots before you swallow them.

"One of the big risks of eating casu marzu is that the maggots can survive the chewing and digesting process and make themselves comfy in your gastrointestinal tract, causing something called intestinal myiasis," says Birnbaum. "For this reason, even many cheese professionals I know say they would avoid the cheese if it was offered to them."

Now you might be thinking why not just remove the maggots from the cheese before serving and you eliminate the health risks, right? Unfortunately, it's a bit more complicated. "It's not that the maggots need to be alive when the cheese is consumed, it's more a matter of them being difficult to kill while inside the wheel," explains Birnbaum. "Once the cheese is ripe and ready to eat, the maggots are quite numerous, and waiting for them to grow into flies would change the cheese's flavor and texture into something totally different, which some say is even more dangerous to eat."

And if you find dead maggots in the wheel, you definitely don't want to eat it — that's a sure fire sign it's gone bad.

Birnbaum says you can refrigerate or place a portion of the cheese in a sealed paper bag until the maggots suffocate to kill them — neither affects the cheese, she explains. And you won't have to worry about wiggling fly larvae in your stomach, that is, if you can get past the fact that you're eating maggots in your cheese to begin with.


What Does Casu Marzu Taste Like?

And about eating casu marzu. You're probably wondering what the heck this sought-after cheese full of maggots tastes like? Well, it's described as acidic and compared to very strong, sharp blue cheeses and mature Gorgonzolas with a mealy texture. Sardinians typically enjoy the cheese with a local flatbread, pane carasau and cannonau, a strong red Sardinian wine.

Although Birnbaum hasn't tried the cheese because she hasn't had the opportunity yet, she's not even sure if she would if it appeared in front of her.