The secret resistance behind the world’s most dangerous cheese

Sardinia’s casu marzu teems with maggots, and might eat through your stomach. Why can’t people stop eating it?

In 2009, the Guinness World Records dubbed casu marzu the most dangerous cheese in the world, specifically pointing out the threats it poses to “human health.” When you come face to face with a round it’s not hard to see why. A Sardinian specialty made by allowing cheese skipper flies to lay thousands of eggs in a wheel of pecorino, casu marzu is served with a host of tiny yet visible larvae alive and writhing in it. (Dead maggots are a sign that the cheese has gone bad.) When you scoop some of the creamy-mealy cheese out of the rind and make to eat it, the maggots protect themselves by coiling up like organic springs and leaping up to half a foot away from danger, all too often onto your face. Some people chill their casu marzu to slow the larvae down, while others place it in an airtight container to suffocate them to death just before eating it to avoid maggoty sparks flying all over. But of course, the grubs are still there.

No one is sure of the exact levels of risk associated with eating this putrid cheese (casu marzu’s literal translation). But food scientists note that letting flies play in dairy risks contaminating it with nasty bacteria like salmonella, and that maggots, as they work through the cheese, produce cadaverine and putrescine, compounds that can be toxic in high doses. They can also trigger allergic reactions in some and survive stomach acid only to set up shop in people’s intestines, causing intestinal myiasis, an afflication that causes abdominal pain, fever, vomiting, gastric legions, anal itch, and bloody or maggoty diarrheic shits — hence the most dangerous cheese in the world moniker.

There’s no standard for making casu marzu. Every town has its own conventions: some use sheep’s milk, others cow, and others still a mix; some rub their cheese with olive oil and others brine it to make it easier for maggots to work through the rind; some drill holes in the rind and others cut the whole top off. This likely accounts for the incredible number of names for the cheese on the island — casu becciu, casu fattittu, casu frazigu, formaggio marcio, and hasu muhidu to name a few. It also means that it is almost impossible to account or control for every risk associated with producing or consuming it.

But if you ever go to Sardinia and ask people about the island’s most notorious cheese, you’ll likely get a bunch of eye rolls and sighs. Many young, urban Sardinians view casu marzu as a gross culinary sideshow and so avoid it, according to Ivo Pirisi, a native Sardinian and operator of the food tourism outfit Tasting Sardinia. More locals still know that most tourists only ask after the cheese because it’s a staple of most disgusting or dangerous food lists and travel show stunts by famous food hosts like Gordon Ramsay and Andrew Zimmern. Food aficionados especially would rather people know their homeland for its wider diet, full of regional delicacies like mele amaro, a surprisingly bitter honey, or its abundance of endemic mountain herbs, than for exoticising, disgust-fueled clickbait articles.

A number of locals are also likely to tell you they wouldn’t know anything about where to find casu marzu. It has been illegal since 1962, after all, when Italy passed a national food safety law. A 2002 EU food safety law, which Italy adopted in 2005, superseding its older regulations, does not lay out specific penalties for selling casu marzu. But it states that producers and distributors can face fines from €1,500 to €50,000 and anything from administrative sanctions on one’s business to one year of jail time, depending on the nature of their businesses or transactions.

Casu marzu, in all its maggoty glory.

Casu marzu, in all its maggoty glory.

Yet for all of the cultural and legal baggage surrounding it, Sardinians still make and eat literal tons of casu marzu when it’s in season in the late summer and early fall — often with moistened pane carasau, a local flatbread, and a glass of strong red wine. No one knows exactly how much of it they make per season, thanks to the informality and illegality of its production and distribution. But by some accounts you’ll find it at most summer festivals or weddings. Other accounts suggest there’s far more demand than there is supply, leading it to retail for up to three times the price of a regular wheel of pecorino.

Some of this reflects the fact that older and rural people grew up with, and have a taste for, the cheese. But even the young and urban folks Pirisi notes usually shy away from casu marzu might partake at some of these events because, looking past trepidations about outsiders’ clickbait fixations, many still consider it a staple of traditional Sardinian fare.

Casu marzu isn’t the only illegal cheese Sardinians still make and consume in spades. Others like su callu, a goat cheese made by drying the milk- and hair-filled stomach of a freshly slaughtered suckling kid in the open air for weeks then scooping out the soft, fiery gloop that forms within it, are even easier to find. “You’ll see cars parked on the side of the street along village roads, and they will have it hanging in the [trunk], waiting for people to stop and buy some,” said Pirisi. “We know they’re not legal. But we make a boast of [making and eating] them. We don’t care.”

From the outside, Sardinians’ insistence on making these challenging cheeses can seem puzzling. But this production and consumption makes total sense once one starts to look at it through the lens of gastropolitics — the use of food to subtly but pervasively advance political arguments. Illegal cheese production offers Sardinians a potent, yet relatively low stakes, avenue to assert their autonomy and the value of their unique identity, both of which many of them believe Italy and the EU all too often step on in favor of sterilized standardization and integration.

Sardinia, which is located to the west of the Italian peninsula in the Mediterranean Sea, has never been like the rest of Italy. A chronically restive Roman province, the Republic and later Empire used the island as a vital breadbasket, but officials and historians largely saw its people as unreliable others at best, treacherous at worst. After the fall of the Empire, the island came under the sway of a succession of decidedly non-Italic powers (and enjoyed a few centuries of independence), only falling under control of the Italian kingdom of Savoy, the power that would later lead the Italian unification effort, in 1718. To this day, many locals speak Sardinian, a language rooted in ancient Latin but tinted by a murky ancient indigenous tongue, as well as Castellano, Catalan, Greek, and Punic influences. British author D.H. Lawrence in 1921 called it a land “belonging to nowhere, never having belonged to anywhere,” and Italy recognized its unique story in 1948, granting it partial autonomy.

Many Sardinians feel a strong sense of difference from their Italian co-nationals. Elisa Ascione, an anthropologist at The Umbra Institute in Perugia, noted that Sardinians who moved to Umbria and Tuscany in the 1960s in search of cheap agricultural land and economic opportunity struggled to integrate into local communities, and faced harassment for their identities and language in school. This and other tokens of disrespect from mainland Italians towards Sardinian identity and culture, as well as a belief that the central state has squandered the island’s economic potential, fuels a powerful sense of grievance against centralizing powers.

“Sardinia has always been treated like a colony,” said Andrea Caruso, a dentist and pro-secession activist in the modern Sardinian capital of Cagliari. “There was never a will from Italy to promote the growth of local cultures… Italy doesn’t care about Sardinia except for the summers,” when its beaches serve as resorts for the wealthy.

“We know they’re not legal. ... We don’t care.”
Ivo Pirisi, operator of the food tourism outfit Tasting Sardinia

These grievances gave rise to an independence movement throughout the 20th century so potent that it spawned radical militant groups that attempted to pull off assassinations, bombings, and kidnappings — mostly from the late ’60s to the mid-’80s but as late as 2004 — to promote their cause. At its peak, the nonviolent pro-independence Sardinian Action Party led a coalition government with communist and socialist parties on the island from 1984 to 1989, and helped push forward laws protecting the Sardinian language and culture from the late ’80s into the ’90s. Political wonks often view Sardinian nationalism as a failed movement thanks to heavy factionalism, infighting, and splintering over the last few decades that has kept it from gaining much ground.

But as late as 2012, a survey showed that 41 percent of Sardinians still want independence and 87 percent want far more autonomy than they currently have under Italy. Franciscu Sedda, an independence activist who, in his own words, has “had the privilege or the fault to found three political parties” throughout the 21st century, believes the only reason pro-independence sentiment isn’t higher is the belief that Sardinia is too poor to survive on its own — a sentiment he vigorously disputes.

In the abstract, it’s hard to tell what cheese has to do with any of this. Although listicles often associate casu marzu, su callu, and their ilk with Sardinia alone, they are not actually unique to the island. Su callu is likely a historical remnant of the way most peoples discovered how to make, and initially made, cheese — by leaving milk in a slaughtered animal’s stomach then trying the resultant schmear out of curiosity or desperation. The Italian regions of Abruzzo, Calabria, Emilia-Romagna, Friuli-Venezia Giulia, Liguria, Molise, Piedmont, and Puglia all have their own versions of casu marzu, stemming either from a common ancestor or a common experience of opting to try maggot-spoiled cheese and realizing that larvae help to ferment it, giving it a harsh but captivating flavor. Neighboring French Corsica has its own version of casu marzu as well. So making these in-historical-fact international cheeses hardly seems, from an external and distant perspective, like an act of national pride and self-assertion.

But cheese has held a special place in Sardinian national consciousness for hundreds of years. In the late 18th century, the Sardinian author and activist Francesco Gemelli pointed to the island’s rich shepherding tradition as a root of its unique identity and future of its economic autonomy; he also called fiore sardo, Sardinia’s flagship pecorino, the island’s crowning cultural achievement. In 1924, three years after the rise of the Sardinian Action Party and birth of modern Sardinian nationalist politics, Italian journalist Pietro Gobetti wrote about the centrality of cheesemaking, especially for growing American consumer markets, to the Island’s economy and psychology. To this day, dairy sheep outnumber Sardinians nearly two to one on the island, and a huge chunk of the population is involved in cheesemaking. Sardinians, Caruso and others say, also often view inland shepherds as the carriers and preservers of the most distinct and ancient local traditions.

So when central Italian authorities decided in the 1960s to modernize the Sardinian economy by industrializing its agriculture, developing mineral and petrochemical plants, and promoting beach tourism, many took this as either blunt disregard for, or an explicit attack on, their traditions and way of life. They also took note of the way that Italian food laws targeted their distinctive cheeses yet, murky on details as they were, carved out space for the continued production of traditional mushrooms and seafood dishes that arguably carry equal health risks, but that were more common in mainland diets.

Although they seem to see it as less malicious, some Sardinians also note that since Italy joined the European Union, the push to dissolve borders has created a flood of cheap meat and dairy products onto local markets, especially from Spain, that has further threatened their shepherding and cheesemaking economy. And while the EU certainly offers (fuzzy) tools for minority groups to assert and try to protect themselves, regardless of their national contexts, Sardinians have not had much luck in using these globalizing institutions to protect their own local institutions.

All of this helps to explain why cheese and cheesemaking are so important to many Sardinians — and why we associate cheeses like casu marzu and su callu with the island and not any of their other historic zones of production. They were seemingly never as functionally or symbolically significant in regions like Abruzzo, and so have largely faded away into relative obscurity in the modern era. Combined with the international rise of traditional and slow food movements, pushing back on industrialized food systems and their increasingly visible flawsfrom the 1980s onwards, this also helps to explain why Sardinians have invested so much energy in trying to protect, and taken on so much risk by actively bucking international law to continue producing, these cheeses.

Rather than wait on official legalization, or lead grassroots efforts in support of legal or technical remedies, most Sardinians just buck the law.

Over the past 15 years especially, regional institutions have tried to find ways to legalize casu marzu. In 2005, the University of Sassari partnered with local shepherds to develop a safe production system, raising flies in standardized and sterile environs and then introducing rounds of standardized pecorino into their clean environs for infestation. In 2007, Sardinia’s autonomous government also declared the cheese a traditional food, claiming it was protected from undue regulations under a 1999 EU law, and in 2015 they got it recognized as a traditional Sardinian food under Italian law.

Unfortunately, the University of Sassari project was a dead end; it failed to answer all the health concerns surrounding casu marzu, and ran up against the popular perception that controlled fly infestations just result in lesser cheeses. And while the EU respects member state food safety decisions and exceptions, including one out of Germany that protected a cheese made using live insects, a legal research paper authored by a student at Wageningen University in 2018 notes that obtaining recognition as a traditional food in Italy only protects domestic production and consumption. It does not carve out a food safety law exemption legalizing the commercial sale of this or any other challenging cheese.

(I asked EU representatives to check on the legal status of casu marzu while reporting this piece, and on any efforts to amend that status. These representatives promised to look into the matter. However, as of publication, they have not yet responded with any official updates on the topic.)

Rather than wait on official legalization, or lead grassroots efforts in support of legal or technical remedies, most Sardinians just buck the law. Doing so allows them to protect cheeses that, while perhaps not beloved by all for their taste or texture, still carry within them a sense of the peculiar story of Sardinian life, as manifested through its hand scrabble shepherds and their products. And it offers this opportunity to protect culture against external, homogenizing forces — to subtly stick it to the man — all without risking that much for those involved in this resistance. While the fines for illegal cheese sales are in theory high, enforcement on the island is sporadic at best; local authorities’ hearts aren’t in the effort.

This may seem like a peculiar form of cultural self-assertion, unique to Sardinia’s agricultural and political history. But it is not. As food historian Fabio Parasecoli recently put it, food often “becomes an expression of political tensions, an arena for ideological negotiations, a propaganda device or a tool that governments can deploy to measure, control, support, or punish.”

Historically, we learn the most about these gastropolitics in terms of state-based coercion, like the American military’s effort to eradicate buffalo on the Great Plains to demolish indigenous societies. However, there’s been a wave in recent years of nations, especially in the EU, using food to assert and delineate national identities and autonomy in the face of large globalizing forces. France and Italy especially insist on defining, labeling, and protecting their own unique foods as a means of asserting themselves as unique entities within the international scrum of Europe. Modern far right groups also seem to be using national foods as symbols to rally people against immigration and the inevitable decay in national cultural identities they believe it will lead to. Food is so ubiquitous, and freighted with meaning, personal or national, that it just makes sense for people, parties, and even nations to use it as a symbolic yet concrete vessel for identity, on which to make a stand.

My interest in the politics of cheese, rather than some gross-out article or rubber-necking tourist impulse, is what drew me out to a little farm half an hour north of Cagliari a couple of years ago, and face-to-face with a round of casu marzu. I’d been asking after the cheese, as discreetly as possible, for a couple of days beforehand, always explaining that I wanted to understand the culture behind it rather than gawp and gawk. And with a little time and effort, I eventually managed to find someone willing to put me in touch with a shepherd who makes the stuff.

I am not the person to turn to for advice on how to navigate the knee-jerk disgust many feel when they hear about casu marzu. I’ve eaten far stranger and in many ways more disturbing things over the years, sometimes out of necessity and sometimes out of pure interest. (I once cooked a feast for over 20 people using nothing but blood, bones, and offal, just to make a point about waste in modern meat production and consumption systems.) Nor am I unfamiliar with eating technically illegal foods, although it’s probably wisest if I don’t go into the fine details on those experiences.

So I can’t say that eating casu marzu was a revelatory taste experience. It tasted exactly like folks told me it would: a very strong, fresh gorgonzola, albeit with a uniquely mealy mouth feel. It’s potent stuff, and any food that kicks you in the face in some way, shape, or form is, in my book, damn good food. Still, it’s not a flavor I’d go chasing after on the regular.

But talking to the shepherd about their history on the land, the traditions that they’ve tied to their goats, and their memories of making these cheeses throughout their life — that stuck with me. Eating food with someone who’s made it, rather than just reading about it in a Guinness book or even buying a round on the grey market and eating it on your own, may be the only way to really understand the politics churned into it. It will certainly hammer home the fact that laws alone can't stop the power of culture.

Mark Hay is a freelance writer, covering food, politics, and sex. His writings have appeared in publications from Aeon to VICE.