In cheese, there is a line.

I like blue cheese. I love a nice Stilton with deep veins. I have no problem with the concept of cheese where mold is part of the appeal. Hell, ever since I watched that episode of Chef! I’ve had no problem with the idea of unpasteurized cheese. What’s the quote? “Gone off milk and bugs living together in perfect harmony”, I think. Seems plausible when I’m picturing a nice Stilton.

However, in wandering the Wikipedia yesterday, I found an entry on the Sardinian cheese casu marzu, and I can say with no doubt that there is a line which I will not cross. “Gone off milk and bugs living together in perfect harmony” — suddenly it doesn’t seem epicurean, it seems very ominous. (More evidence for my theory that people isolated on small islands go off.)

Here’s the text of a “news” piece that is quoted all around the web about this cheese, just in case that entry didn’t have enough colour for you:

(Nuoro, Italy) In the kitchen of his rustic farmstead atop Sardinia’s Mount Lollove, Giovanni Antonio Costa smiles through missing front teeth. It’s time for a clandestine treat. After pouring a glass of strong homemade wine, he sprinkles thin Sardianian bread with tap water to make it easier to fold. Then he extracts from a creaky cupboard a brown lump the size of a human head and deposits it on the rough wooden table. It’s a cheese. And it’s alive. Drilled Cheese. The round of the pecorino is filled with thousands of wriggling, transparent maggots, the larvae of flies. The 52-year-old Mr. Costa grins as he dips his fork in.

“We all go crazy for this stuff,” he says. “But because it’s prohibited, you can’t buy it anywhere.”

As the worms merrily jump up and down, cavorting all over the table, one of Mr. Costa’s five brothers prepares a tasting by wrapping a morsel in the thin bread. “You don’t have to look at them-just put the thing in your mouth,” he urges, chewing a mouthful of the stuff. He adds a piece of local folklore: “It’s an aphrodisiac.” This moving delicacy is known as casu marzu, which is Sardinian for rotten cheese. It first happened, like many culinary treats, accidentally. Flies laid eggs inside the cheese mass left outdoors to ripen. The eggs hatched into myriad maggots that promoted fermentation. Mountain farmers produce sheep-milk cheese with worms in Northern Italy’s Piedmont and Bergamo areas. But only on Sardinia has it acquired something of a cult following. It is widely, but not openly, eaten.

Italian health authorities consider cheese with worms damaged goods. Selling it or serving it can be punished with a hefty fine. That’s why Mr. Costa offers his casu marzu in the family’s private kitchen, rather than in the dining room of the inn his family also runs. Though the ban is enforced only sporadically, health inspectors try to ensure that Sardinia’s casu marzu remains an illicit pleasure.

The cheese cost $7 a pound and up-compared with $3 to $4 for a normal pecorino-and has to be procured through a kind of black market . The outlaw status adds to the cachet. Casu Marzu appears as the centerpiece of social occasions such as weddings and birthdays. “I tasted it last at a friend’s bachelor party a few weeks ago,” says Giuseppe Pirisi, a Nuoro agricultural specialist with an interest in Sardinian folklore. “It’s not that we like the worms. What we like is the cheese itself, as it’s part of our culture.”

The cheese itself tastes rotten. Enzymes produced by the maggots cause the cheese to ferment and its fats to decompose. The result is a viscous, pungent goo that burns the tongue and can affect other parts of the body. One neophyte experienced a strange crawling sensation on his skin that lasted for days. And some of the wiggling worms jump straight toward the eyes with ballistic precision. To protect the eyes, some Sardinians recommend holding a hand over the sandwich. Though worms can be removed from casu marzu, many Sardinians don’t see a reason to bother.

“It would make me sick to see a worm in a cake or a sweet, but I don’t mind when it’s inside the cheese,” Mr. Costa says. “In fact, the presence of live worms is often regarded as proof that the cheese remains good. A really bad cheese wouldn’t support maggots, which would die and make the casu marzu truly toxic.”

Skeptics say it’s already toxic. “Casu Marzu’s anomalous process of fermentation and decomposition can bring in toxins and bacteria that are damaging to the health,” warns Antonio Carboni, director of animal-products agency in Sardinia’s autonomous government. “However, I have never heard of anyone falling ill after eating this stuff. Sometimes, it tastes real good.”

Some of Sardinia’s culinary stars agree. “I personally like casu marzu a lot,” says Mauro Frau, chef of the La Fregola restaurant in Porto Rotondo, an exclusive resort favored by the international yacht set. “But if I were to try serving casu marzu to my customers here, they’d simply throw it in my face with disgust.”

So might many ordinary Sardinians, especially women, who tend to be more finicky than men about live worms in their food. “I can’t stand this thing when the worms are inside,” says Mr. Costa’s 80-year-old mother, Antiocha, as hers sons are happily feasting on larvae. “When I was young, a lot of cheese would go rotten, so I’d just put it out in the sun and wait for the worms to get out before having a taste.”

Martina Cassitta, owner of the Monte Pino farmstead in northern Sardian, also won’t touch the larvae-filled cheese when any of her pecorino becomes rotten. She has a different method for getting rid of the worms, which she calls microbes because, like many Sardinian farmers, she believes the maggots come from the milk itself, and not from flies. Ms. Cassitta simply seals the cheese in a big paper bag and waits. “You can just hear the deafening tac-tac-tac as the microbes gasp for air and jump out of the cheese, hitting the paper,” she says. She displays a piece of now-wormless casu marzu that looks as if it had been invaded by termites. “Once the noise ends, it’s ready to be eaten.”

I found some pictures, but I’m not linking them because I don’t want to have to look at them.