It’s like a culinary riddle: what is a food made of only three ingredients where the main processing is done by invisible workers; which can be eaten as an appetizer, condiment or dessert; and which is prescribed by doctors to cure ailments?

Need a hint? It’s also a dairy product… that can be eaten by the lactose-intolerant.

The answer: Parmigiano-Reggiano.

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Much more than a fancy way to say “parmesan”, Parmigiano-Reggiano is a cheese that can only be made with extremely precise ingredients, in an extraordinarily particular process, in a 10,000-sq-km geographical area of Italy so carefully defined that you can make Parmigiano on one side of the small city of Bologna but not the other.

The result of all that labour and legality is – as many cooks, nutritionists and Italians alike will tell you – a practically perfect food.

It is a panacea – something that gives health to everything it touches

There is Parmigiano’s taste: salty but sweet, grassy but nutty, sharp but rich. There’s its texture: hard but grainy, popping with white crystals. There’s its evolution as it ages: a two-year-old cheese smells like fresh fruit and tastes sharply sweet; a three-year-old wheel reminds you of dried grapes and nutmeg, tastes more savoury and complex, and crumbles more easily in the palm.

And there is its nutrition, a result of not only its ingredients but of the ageing process. Pound for pound, Parmigiano can compete with almost any food for calcium, amino acids, protein, vitamin A. “Parmigiano has a thousand benefits, even for health,” said chef Anna Maria Barbieri. “It is, let’s say, a panacea. Something that gives health to everything it touches.”

I hope so, because at Barbieri’s restaurant Antica Moka, a Michelin-listed restaurant in the heart of Parmigiano country in Modena, I eat the cheese until I feel like I’m going to burst. From a 24-month wedge as long as my forearm, I use the spade-shaped slicer, almost as ubiquitous in Italian kitchens as Parmigiano itself, to slice off shards for antipasto. I feast from a small cup of farro soup drizzled with crema di parmigiana (parmesan cream) accompanied with Parmigiano bread. And then there’s Parmigiano again as a primo (first main course), twice over: tortellini in a sauce of Parmigiano, drizzled with balsamic vinegar of Modena, served in a fried Parmigiano bowl.

“Sometimes people tell me, ‘But Parmigiano, you put it in everything!’,” Barbieri said with a chuckle. “It’s my weakness. I really do put it everywhere.”

Like so many others in the production area, Barbieri grew up with Parmigiano. She remembers dairy farmers bringing their milk to her family’s cheesemaking factory. As a little girl, she would accompany her grandfather, one of the first members of the Parmigiano-Reggiano Consortium, the association of producers established in 1934, on his trips to factories to verify the quality of each cheese wheel and give them their distinctive stamp of approval.

“For those of us from Emilia-Romagna, Parmigiano is our ‘daily bread’,” Barbieri said. “It accompanies us throughout our lives.”

In Italy, particularly this part of Italy, Parmigiano is no mere luxury. It is a birthright. It’s grated over countless bowls of soup and dishes of pasta. At aperitivi with friends, it’s as crucial as a glass of wine. At weddings, it’s as abundant as well wishes.

A friend from Turin told me that when she came to the UK to study, she tucked three staples into her suitcase: olive oil, tomato passata and Parmigiano-Reggiano. When I went to see a Roman friend visiting London, I smiled to see a wedge of Parmigiano on the kitchen counter of her rented flat. In my own home with my Italian husband, our refrigerator always is stocked with milk, eggs – and Parmigiano.

Parmigiano’s devotees are hardly new. The 14th-Century poet Boccaccio set his maccheroni (pasta) eaters on a mountain of the cheese. The 17th-Century painter Cristoforo Munari placed Parmigiano at the centre of his kitchen scenes. The Pope sent England’s King Henry VIII 100 wheels as a gift. The French playwright Molière asked for Parmigiano on his deathbed. When the Great Fire of London bore down on the house of Samuel Pepys in 1666, the writer buried a wheel of the cheese to protect it.

Few of these fans would recognise much of what’s sold today. The white flakes many of us grew up shaking from a green can aren’t parmesan, not even close. Within the EU, both Parmigiano-Reggiano and its anglicised version, “parmesan”, are legally registered terms protected by the PDO – protected designation of origin – label since 1996. But in the US, the law protects only the name “Parmigiano-Reggiano” (In the EU, those green Kraft canisters are labelled “Parmasello”).

In Italy, Parmigiano is no mere luxury – it is a birthright

Worse, much of what goes for grated cheese in the US isn’t cheese at all. Tests by Bloomberg News found that some versions included up to 9% wood pulp – an anti-clumping agent known as cellulose. Parmigiano-Reggiano doesn’t have this ingredient or any additives or preservatives at all, for that matter, salt aside.

Then there’s fraud. At the headquarters of the Parmigiano-Reggiano Consortium in the city of Reggio Emilia, president Nicola Bertinelli, whose family has made Parmigiano at their farm since 1895, asked me to take a guess: out of 10 wheels of Parmigiano-Reggiano sold in the world, how many are real?

“One?” I guessed, expecting I’d be too cynical.

“Exactly. One,” he said.

After all, there’s a great deal of money in Parmigiano. When the US’s wholesale chain Costco sold wheels for $900, it made headlines – not least because it was a bargain.

The reason Parmigiano is so pricey lies in its precision.

There are only three ingredients: milk, salt and rennet, the enzyme that curdles milk. The milk comes from four cow breeds – the most famous of which are the vacche rosse, a rare breed of red cows that number just 3,000 total, or 0.01% of all of the dairy cows in the EU alone. But it’s more than that. “The secret of this cheese isn’t just the type of cow that produces the milk, but what the animals eat,” said Luca Caramaschi, the owner of Parmigiano factory Caseificio San Bernardino.

Bertinelli outlines the rules. The production area is exclusively the provinces of Parma, Modena, Reggio Emilia, Mantua (to the east of the Po River) and Bologna (to the west of the Reno River).

At least 50% of the cows’ dry food must come from hay, at least 75% of the hay must come from the Parmigiano production area, and at least 50% of that production-area hay must be produced on the farm where the cow itself was born and bred.

“Why is this zone so precise? Because only here – naturally, historically, geographically – does the hay of the cattle have three specific strains of bacteria: the ‘three friends’,” Bertinelli said. “If these three bacteria are present in production, they trigger processes where the milk leads to the development of particular aromas, flavours and tastes – and to specific acidity levels, which is why [the cheese] can be preserved for so long.”

Without these “friends”, even the finest of cheesemakers and vacche rosse wouldn’t be able to produce Parmigiano.

I watch the invisible workers in action at the Caseificio Sociale Cooperativo Pongennaro. Like 85% of Parmigiano factories, it’s a cooperative, owned and run by groups of small local farmers. And at 08:00, production already is in full swing. Half of the milk was delivered fresh from the cows the previous evening; overnight, the fat rose to the surface. It’s been skimmed off for butter. The rest of the milk was brought this morning, full-fat. Both are combined in a copper cauldron, the reason Parmigiano is called semi-grasso – “semi-fat”. It takes 14 litres of milk to make 1kg of Parmigiano; 550 litres to make one wheel.

One of the cheesemakers heats up the cauldron and adds the whey starter – the culture rich with good bacteria that kick-starts the fermentation process – from yesterday’s production.

“Now a kind of battle takes place: the good bacteria will defeat the bad bacteria by eating everything,” said the consortium’s Cristiana Capelli, who is showing me around. “The good bacteria start looking for more food and begin to eat the lactose of the milk. The cheese is cleaned, safe for a long fermentation.” This explains why the only preservative used, or needed, in Parmigiano is salt. It also explains why Parmigiano is safe even for the lactose-intolerant.

As we watch, one of the workers adds rennet to curdle the milk. After two minutes, the cheese begins to separate. In nine minutes, it’s coagulated completely. The next step is churning, first slowly and carefully, then faster and faster. The temperature goes up to about 45C. One cheesemaker dips his hand into the cauldron. “Watching the temperature is not enough,” Capelli said. “They keep their hands inside because they have to find out how the milk is behaving. Milk is different every day depending on air, the temperature, everything.”

The mix has turned from creamy white to butter-yellow; the granules look like rice pudding. The cheesemaker squeezes them to test their readiness. It’s time. The heat switched off, the mixture is left to rest for an hour. The liquid, which weighs 10 times more than the granules, pushes out both air and bad bacteria.

Then comes the moment we’ve been waiting for. At the bottom of each cauldron, 2.1m deep, a 100kg block has formed. The men push it up with a paddle and cut it in half: two 50kg wheels of what looks like packed-together rice.

The next steps of the process sound like nothing so much as going to a spa. In the sala di riposo, or “resting room”, the cheese loses weight: put in a mould, the wheel rests under a weight to squeeze out excess water. It’s stencilled with the stamp of origin, outlining the date, factory and DOP label. Then it goes to the pool: each cheese is plunged into a bath of water made up of 33% salt. Through osmosis, the cheese sheds fat and whey. After 20 days of brining, when the salt has penetrated 3cm or 4cm deep, it’s left in the sun to dry.

Only then, finally, does the cheese go into the ageing room.

Here, over the next two years, or three, or even 20, as in the case of one wheel that Caramaschi shows me at Caseificio San Bernardino, the magic happens. The salt penetrates the core of the cheese. The bacteria keep up their work. The cheese transforms from a block of milk and fat and salt to something else entirely: Parmigiano.

“Over time, all of the aromas and flavours that there are from the territory are concentrated,” said Caramaschi. “It’s much like what happens with wine.”

In a year, professional testers from the consortium come to check each wheel, tapping it with a hammer-like tool and listening for evidence of inconsistencies, like cracks or holes. If it’s approved, it gets a final firebrand of quality. If not, it’s either judged a second-quality cheese, which must be labelled mezzano – middle quality – and can’t be aged further. Or, if beyond hope, the rind and its stamps are scraped off completely, erasing forever any association with Parmigiano.

Some 8% of all the wheels produced in the region meet one of these lesser fates. The rest go on to be exported across Italy and around the world.

*

A little later, I find myself standing in an 800-year-old chapel on Caramaschi’s estate. A painting above me shows the archangel Gabriel carrying a banner – not out of the ordinary, except for what’s depicted on it: San Lucio, the patron saint of cheesemakers, stirring a copper kettle of milk over a fire to make Parmigiano.

“This is where I was married 30 years ago, where my sons were married, where my nephew and my sons were baptised, and where my father lies,” Caramaschi said. “It’s become the church of the family.”

Before Caramaschi’s great-great-great-grandfather began making Parmigiano here in the 1700s, this was a small village, complete with a dairy farm. The church is no coincidence. Parmigiano was first made under the guidance of Benedictine monks about a millennium ago.

Without knowing what bacteria were, cheesemaking must have seemed mystical, even miraculous, to its first practitioners. So, too, the food’s health benefits.

Traditionally, mothers gave rinds of Parmigiano to their teething babies. Even today, it’s prescribed in Italy to the old, the young, the sick. Because the good bacteria gobble up the cheese’s lactose, 26-month-old Parmigiano is safe for the lactose-intolerant. Thanks to that same breakdown of bonds, it’s also easier to digest, its proteins and nutrients are easier to absorb.

“Meat proteins need to be broken down into amino acids, which takes four hours for beef,” Bertinelli explained. “But thanks to the natural process of Parmigiano, they’re already broken down, so it only takes 45 minutes.” That means Parmigiano is ideal for those who need an immediate infusion of proteins, like athletes. Parmigiano also has nine free amino acids, the kind easily absorbed by the body – one of which, tyrosine, shows up in the white, umami-flavoured crystals that develop.

Parmigiano is a veritable nutritional supplement, capable of providing a high amount of vitamins and proteins in a few grams

Then there are the nutrients. A single ounce (28g) of Parmigiano has 9g of protein, 2g more than beef, and 321mg of calcium, nearly 10 times more than milk. It has 12mg of magnesium (more than salmon), 28mg of potassium (about a third as much as banana) and 0.12mg of vitamin A (nearly as much as the same amount of raw carrots). There’s zinc and iron, copper and manganese, biotin and vitamin B6.

“Parmigiano is a veritable nutritional supplement, capable of providing a high amount of vitamins and proteins in a few grams,” said Florence-based nutritionist Valentina Fratoni. She recommends it to children, to weight lifters, even to those expecting.

“Even pregnant women should eat Parmigiano as an important source of calcium for the health of their bones and for the formation of the skeleton of the unborn child,” Fratoni said. “Although Parmigiano is made with raw milk, therefore not pasteurised, its long maturing, at least 12 months, prevents any danger.”

*

I end my exploration of Parmigiano much where I began: eating. I’m back home in London, far from the glossy red cows and copper cauldrons and 800-year-old churches of Parmigiano country. As I pull out a wedge, I remember what Barbieri said.

“At 24 months, I like to eat it like it is,” she told me. “With hot bread out of the oven. Or even with nothing – then you can really get a feel for it and its flavour, so delicious you can taste it even with your eyes closed.”

Is Parmigiano a perfect food? I’m not sure. But right now, standing barefoot on a chilly London evening, it’s a taste of the things I love about Italy: its beautiful countryside and culinary passions, long traditions and little miracles. And for me, that’s enough.

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