The panel tasted the six oil samples according to a strict protocol, which, like each feature of the panel test room itself, was prescribed by Italian and European law. Cradling the glasses in their palms like brandy snifters to keep the oil warm, they smelled it carefully, jotting down the fragrances they perceived. They took a mouthful of oil. And then, as if they’d all been stricken by an oil-induced seizure, they began sucking in air violently at the corners of their months, a technique known as strippaggio, which coats the taste buds in an emulsion of oil and saliva, and wafts the oil’s aromas up into the nasal passages. After the first volcanic slurps, the strippaggi grew softer and more meditative and took on personal notes, the marchesa’s wheezy and almost wistful, the businessman’s deep and wet, as if he were gargling Epsom salts. After tasting and retasting each oil for ten to fifteen minutes, and periodically cleansing their palates with mineral water, they recorded its flavor, aroma, intensity, texture, and other characteristics on a scoring sheet.

The tasters pottered in their cubicles for the next ninety minutes, snuffling and slurping and musing over the oils. Finally, after evaluating the last of the samples, they stood and stretched like people rising from sleep, and moved to the conference table in the middle of the room. Here they enjoyed their long-awaited cigarettes and coffee, while the panel leader, Alfredo Mancianti, collated their scoring sheets. “The tasters themselves don’t score an oil,” Flavio Zaramella, the Milanese businessman and president of the Mastri Oleari, told me. “They just identify and quantify the sensations they perceive in it. It’s the panel leader who actually assigns a score to the oil, by making a composite of their eight assessments using robust statistical methods.”

Looking over the panel leader’s shoulder as he worked, I saw that the eight tasters had been remarkably consistent in their appraisals, describing the texture and personality of each oil in similar ways, and identifying the same subtle flavors and fragrances in each—artichoke, fresh-cut grass, green tomato, kiwi.

“The tonda iblea from southern Sicily was memorable, with those afternotes of artichoke and green tomato,” Zaramella told the other tasters. “But all in all, I think the best full-bodied oil was the Marcinase DOP Terra di Bari from Puglia.” The others nodded, though one taster said she preferred the Villa Magra Gran Cru from Tuscany because it was more balanced and harmonious.

By now I found it hard to sit still. Artichoke? Fresh-cut grass? They hadn’t been tasting first-growth Bordeaux, for heaven’s sake, but liquid fat. No doubt these oils had been made with great skill, “cold-pressed” and all that, but artichoke? Green tomato? Kiwi?

Something in my face must have alerted Zaramella to my skepticism. He stubbed out his cigarette, hopped to his feet, took my arm, and steered me into one of the tasting cubicles. “Oil talk sounds like effete nonsense, until you actually put a good oil in your mouth,” he said. He began pouring samples of oil into tulip glasses and placing them on the warmer beside me, capping each with a glass wafer to hold in the aromas. When the thermostat light went out, indicating that the oil had reached twenty-eight degrees, Zaramella showed me the approved oil-tasting technique: how to smell the sample deeply several times, trying to clear the mind between sniffs; how to take a small sip and to roll the oil around with my tongue to coat the inside of my mouth; and how to perform the loud, slurpy strippaggio. From time to time he reminded me to clean my palate with mineral water, or with a bite of a Granny Smith apple.

For the next hour, under Zaramella’s direction, like someone beginning to study ballet or yoga or violin with a master, I made my first brief foray into the vast, largely uncharted continent of extra virgin olive oil. I learned that oils made from different olive varieties, or from the same varieties grown in different places, can be every bit as diverse as wine from different grape varietals: the straw-colored casaliva oil from Lake Garda was almost sweet, with hints of pine nuts and almonds, while the emerald green moraiolo from central Tuscany was so peppery it left tears in my eyes and a lovely sear at the back of my throat. And sure enough, the tonda iblea from the hills of southeastern Sicily had distinct green tomato and artichoke overtones, just as Zaramella and his colleagues had said. Tasting these oils was like strolling through a botanic garden, touring a perfume factory, and taking a long drive through spring meadows with the windows down, all at the same time—equal parts scientific analysis and lingering, attentive hedonism.

I raised the last sample Zaramella had poured for me, sniffed it perfunctorily, and sipped. Then, after a swirling moment of bewilderment and dawning disgust, I spat it into the sink. Something was wrong with this oil: after the tart, intensely fresh-tasting essences I’d been trying until now, it felt flabby and coarse in my mouth, and tasted like spoiled fruit.

Zaramella laughed his gruff laugh. “I brought the supermarket oil last,” he said, “because it would have ruined your palate for the good ones, as surely as if you’d gargled cat piss.”

He pulled down the brown lab bottles from the shelf on the wall, and set them in a row on the conference table. “Now comes the fun part,” he told me. “You have to figure out precisely what’s wrong with this last oil. It’s like being a detective. Or a coroner.”

He opened the bottles one by one and handed them to me, telling me to try to memorize each scent. The bottles contained a stunning range of reeks, stenches, and pongs, to which their labels—“rancid,” “fusty,” “winey/vinegary,” “muddy sediment,” “metallic,” “esparto,” “grubby”—hardly did justice. Then, after several bites of the apple and a lot of deep breathing to cleanse my palate, I sampled the oil again, sniffing and tasting and trying to put names to its flaws. I thought I recognized several, and jotted them down on a profile sheet.

When I’d finished, Zaramella drew me out of the cubicle and sat me down at the conference table, seated himself across from me, lit another cigarette, and took a voluptuous drag. He scanned my sheet. “Pretty good,” he grunted, exhaling a cloud of smoke that briefly darkened the room. “‘Rancid’ and ‘fusty’ are both there. But you missed a few. The winey/vinegary is strong, and there’s noticeable muddy sediment, too.” He picked up the bottle of supermarket oil I’d been tasting. “You know, according to the law, if an oil contains just one of these defects—one hint of fusty, a trace of brine—it’s not extra virgin grade. Basta, end of story. In fact, with the flaws this oil has, it’s classed as lampante: ‘lamp oil.’ Which can only be legally sold as fuel: it’s only fit for burning, not eating. Trouble is, the law is never enforced.”

Suddenly he banged the bottle down on the tabletop, making coffee cups and ashtrays hop and rattle. “This is what nearly everyone in the world thinks is extra virgin olive oil! This stuff is killing quality oil, and putting honest oil-makers out of business. In wine, you can trust the label: if it says ‘Dom Perignon 1964’ then that’s what’s in the bottle, not last month’s Beaujolais Nouveau. In fact, champagne and Beaujolais support each other, spreading the prestige and brand recognition of French wine up and down the quality scale. But olive oil labels all say the same thing, whether the bottle contains a magnificent oil or this schifezza …” He pointed the neck of the bottle at me like a gun, then lifted his glasses to read the label. “It says what every olive oil says: 100 percent Italian, cold-pressed, stone-ground, extra virgin …”

He shook his head, as if unable to believe his eyes. “Extra virgin? What’s this oil got to do with virginity? This is a whore.”

Then, with the same precision he’d shown in the taste test, Zaramella catalogued the crimes widely practiced in the oil business. He described the deodorizing equipment he’d seen in Spanish mills, particularly in Andalucía, where it is illegally used to remove the bad flavors and aromas of inferior oils in order to sell them as extra virgin. He condemned the widespread practice of labeling heavily refined oils “pure” even though the refining process had stripped them of nearly all of their health benefits and sensory qualities, “light” although they contained the same number of calories per gram as other oils, and “organic”—from olives grown without pesticides or other chemicals—when in reality they were made from ordinary olives. Small-time oil crooks colored cheap soybean or canola oil with industrial chlorophyll, dumped in beta-carotene as a flavoring, and sold the mixture as extra virgin olive oil, in bottles adorned with Italian flags and the names of imaginary producers in famed olive-growing regions like Puglia or Tuscany. More sophisticated, large-scale frauds, he explained, required skilled chemists and multimillion-dollar laboratory facilities, and involved networks of conniving customs agents, businessmen, and government officials. Zaramella identified the headquarters of oil fraud throughout the Mediterranean, naming refineries and factories in Lugano, Switzerland; Málaga, Spain; Sfax in Tunisia; and elsewhere throughout the Mediterranean, where bogus extra virgins were fabricated. He reviewed the countries throughout the world where fake extra virgins were sold, and explained why the US was the best place on earth to sell adulterated oil.

In the coming year I spent considerable time with Zaramella, at the Milan offices of the Mastri Oleari and at oil tastings and conferences throughout Italy. I learned of his penchant for big, creative schemes and long odds: at different times in his career, he’d founded a thriving highfashion firm in Milan and traded petroleum futures through an offshore company registered in Wyoming. On a wall in his office was a map of Somalia, where, in 1987, as the head of a humanitarian aid project, he supervised the construction of a high-tech hospital in Baraawe, a city on the Indian Ocean. “I got everyone working together: Communists, Catholic priests, Muslims, professors, illiterates, anyone with the will to get things done,” he recalled. Two months after the hospital was completed, it was destroyed in the civil war. “Generosity is the purest form of egotism,” he said with a shrug. Zaramella spoke of his abdominal cancer, for which he’d undergone four operations, and of the remarkable therapeutic properties of extra virgin olive oil against numerous conditions, including cancer; his illness, he said, had given him a special sensitivity to the healing qualities of oil. And he described how he’d first become interested in olive oil fraud twenty years earlier, after he started making oil from the trees on a small farm he’d bought in Umbria, and found that the farmer who tended them had been swindling him by cutting his olive oil with cheaper sunflower-seed oil. He said he was devoting the remaining years of his life to his biggest, most difficult scheme of all: redeeming the olive oil business from fraud.

Though his operations had left him gaunt, Zaramella still had the mellow baritone and plump, animated face of the 120-kilo epicurean he’d been before his illness. “My fight is a civic responsibility,” he once told me, “to the thousands of honest oil-makers who can hardly make a living in this distorted market, and to millions of consumers who are being deprived of the therapeutic properties of quality oil. Real extra virgin olive oil contains powerful antioxidants and anti-inflammatories which help to prevent degenerative conditions—like my cancer. Fake extra virgin has next to none of them. Great oil is the essence of the Mediterranean diet. Bad oil isn’t just a deception, it’s a crime against public health.” Zaramella’s dedication to olive oil went beyond a sense of justice or the desire for a cure. Once we stood in his grove near Assisi in springtime, when yellow lilies were blooming among the trees, and looked out over one of those hillsides where Saint Francis had once sung odes to the birds and the sun and the sky. “Since ancient times, olive oil has stood for purity, health, holiness,” Zaramella said softly, almost to himself, in a voice resonant with emotion. “I’m not a religious man, but for me, olive oil is sacred.”

Here was Flavio Zaramella, a merry atheist, speaking of olive oil’s sacredness, a viveur with a terminal disease dedicating his last energies to oil’s healthfulness. Standing with him among the olives and lilies of Saint Francis, I first realized that olive oil did something special to people. Just as oil, a powerful solvent, brings out essential, sometimes unexpected flavors in food, it also reveals the essence of certain people: their hidden contradictions, their secret passions and dreams. It gets under their skin, seeps into their minds, and colors their thoughts, like no other food I know. As I went deeper into oil, I began to see this condition in many places. I recognized its symptoms in octogenarian olive farmers and nonagenarian millers, as well as eager young oil executives at multinational food companies. I saw it in the head of a food cooperative who made oil, at enormous risk, from olive groves confiscated from the mafia, and in monks who made oil from the thousand-year-old trees on their monastery grounds. I met politicians, union leaders, European Union regulators, historians, archaeologists, chemists, agronomists, and botanists, all of whose faces lit up when the conversation turned to oil, and who always had a story to tell, funny or shocking or sad. Even shady characters who’d grown rich making fake oil by the tanker-load spoke wistfully of their childhoods spent at the olive mill, and of the life lessons they learned there. In every eye was the same oily glint of unfeigned fascination with a substance they’d do things for that they’d do for nothing else on earth. All these people suffered from the same condition. They were obsessed by oil.

I began to pay closer attention to this rich, slip...