The super chocolate bar called Good & Evil

Christopher Curtin, the West Chester chocolatier, was about to offer a taste of the finest chocolate bar to ever grace the planet, as he put it - a claim that, for what it lacked in modesty, was sounding less improbable by the minute.

It was created, he said, presiding in his Éclat Chocolate shop, from wild-growing cacao called Pure Nacional, the rarest of fine-flavored beans rediscovered in the high jungle of Peru after having been thought, for almost a century, to be extinct.

And not from just any harvest. No, he took two flights, and a two-day SUV trek, unfortunately involving a collision with a local dog, to see it for himself, with New York celebrity chef Eric Ripert in tow: It was the first-blush April crop above the rushing headwaters of the Amazon, the premier cru, as they call it in vineyard country.

And rustic: Some growers still hauled out pails of beans on their burros.

It was hand-sorted ("Six times!" Curtin watched at the farmstead and counted) to weed out any beans with the barest nick or imperfection that might foretell bitter notes, then meticulously roasted and conched, its flavor teased out with 135-year-old antique Lindt stone rollers in Switzerland, "petted," it's called in the trade; rocked ceaselessly back and forth like a baby in a cradle. For 60 hours.

And that was before Curtin and his crew got hold of it - this pride of Marañón Chocolate's co-op of small farms near Ecuador. In his shop on High Street, it was aged for three months at 65 degrees, then melted at a notch below body temperature, a precise flick of nibs - grindings of roasted beans - folded in to give it an occasional kick of crunch.

It was indisputably dark chocolate, untouched by milk.

But it was unusually, and somewhat mysteriously, light.

Curtin was giving his account by the cooling tunnel in the kitchens of his bonbon of a shop in the heart of the Chester County seat, just down from the courthouse.

It was early October, more than a month before Thursday's New York launch of the bar, on the eve of the city's Salon du Chocolat, de rigueur for any chocolate debutante looking for notice.

The chocolate on Curtin's stainless steel table had been molded into a 2.6-ounce bar - a chocolatier's version of a rare-vintage wine, or say, a superb one-off Belgian beer, or maybe that pampered Panamanian coffee that, not long ago, was fetching upward of $100 a pound.

It was 72 percent cacao.

But that wasn't the only thing giving it buzz.

The bar would be called Good & Evil: The Pure Nacional pods contain an uncommon combination of white and dark-purple beans. So that could be the reason for the name. (And it is, in fact, the reason for the light color of this particular dark chocolate.)

But that's not it. The "good and evil" refers to Curtin's high-profile partners in the gambit - the celebrity chefs Ripert of New York's four-star Le Bernardin, and (evil?) Anthony Bourdain, his globe-trotting bad-boy counterpart on a live road show they host called, well - what a coincidence! - "Good vs. Evil."

The bar would retail, and will now that the wait is over, for $18 - steep, perhaps, for lunchers used to landing a $1.70 dog at Wally's Wiener World, the cart up the block from Éclat.

But if you think of it not so much as candy as a trophy, an exemplar, a brief, shining moment of chocolate ephemera - a shooting star, so to speak, in a murky milky way - well, that is exactly how Chris Curtin would like you to think of it.

It was made for love, he said, not money.

In total, he procured 1,200 pounds of beans, roughly a half ton.

You might get 50 candy-rack bars from one pound of low-grade beans. But a gourmet, 72 percent cacao bar like this? Paid for in cash in the field at 7 percent above fair-trade price? Harvested by family farmers - not the forced child labor (Ripert went along to specifically check this out) that has embarrassed African growers?

That same 1,200 pounds might yield fewer than 5,000 bars, about five or so per pound, less than a tenth of what Big Candy can squeeze out selling cheap, 72 percent sugar bars.

These days industrial cocoa beans are loaded on freighters in Africa bound for Philadelphia, where more than 75 percent of America's raw cocoa is landed, most of it at Pier 84 on the Delaware, most destined for major grinders - Barry-Callebaut, Hershey, and Blommer.

But often the beans have been stored for a year or more by farmers waiting for prices to climb. And they're routinely sprayed with fumigants and pesticides, the better to ward off mildew, mold, and fungus.

What if they were handled another way?

"We wondered," Curtin said. "What would it be like to make chocolate perfectly . . . no corners cut, no cost spared, to shoot for the moon?"

If a single bean fell to the ground in Peru, it was out.

Fermentation temperatures were watched like a hawk.

Pods were split on rocks, not with machetes, to better protect the beans.

Curtin and Ripert make for an odd couple - Curtin pink-fleshed, trained in the finer chocolate houses of Europe, given on occasion to a straw hipster hat; Ripert eternally tanned, silver-haired, pouting lips, a French-looped scarf routinely draped around his neck. (The reputation of his Le Bernardin is beyond reproach. But he has a branch cafe of lesser distinction in Philadelphia's Ritz-Carlton, which is where Monica Glass, then the pastry chef, introduced him to Curtin.)

In photos of their journey last April, there is Curtin in a nursery of Pure Nacional seedlings, and Ripert balanced in a river canoe. They feasted on ceviche in Lima, on soulful chicken soup cooked over open fires in the villages beyond Chiclayo in Peru's northeastern reaches, the same region explored in the 1930s - at lower elevations - by the intrepid British geneticist F.J. Pound searching for wild cacao resistant to a disease called witch's broom that was threatening the world's cocoa supply.

Curtin said a far more recent expedition - American fruit merchants on the hunt for exotic flavors of bananas - stumbled on the Pure Nacional, which for decades had disappeared from nearby Ecuador and was thought extinct.

Scientists from the U.S. Department of Agriculture went on to confirm the finding, then joined with Peruvian farm agents to help protect and expand plantings on the farmers' small holdings in the remote Marañón Canyon.

So the chocolate bar beckoned, its foil wrap unpeeled on the table at Éclat.

It is best to let a bite linger on the tongue.

And if you do, the subtle fruitiness emerges, and perhaps a woodsy hit of forest nuts, but very definitely - and differently from the beans just a year before - a bright, enchanting note of dark cherry.

It was lush, almost creamy, without a trace of bitterness, or the tart, brittle waxiness that can make high-cacao bars more a chore than an easy pleasure.

Yes, it was astonishing good chocolate.

The finest in the world?

I regret to say I haven't tried all the others.