The perfect scam? Prove this isn’t a 286-year-old cocktail recipe from Philly’s oldest secret club.

In the plush confines of the Metropolitan Club last week, insulated from the unseemly hustle of Washington, by thick drapery, brocade wallpaper, and the fortifying security of old money, Christian D'Andrea gestured with a flourish toward a silver punch bowl that, he promised, held one of Philadelphia's greatest and longest-held secrets.

That is, the original Fish House Punch. The concoction, crafted by America's oldest, most secretive, and arguably most exclusive club, State in Schuylkill, dates to 1732, predating what's widely considered the oldest American cocktail, the Sazerac, by more than a century. The lore of the punch, and the club that created it, includes a (probably apocryphal) legend of George Washington on a three-day bender and other (likely true) tales including visits by as many as 10 presidents, as well as the Marquis de Lafayette, who donned the required white apron and straw hat to help cook his own meal, per club tradition.

A sort of Ivy League P.T. Barnum, D'Andrea — a Reston, Va., author and filmmaker who created the Weather Channel series Hurricane Hunters — claims he was combing through a dusty, rare-books archive "somewhere in the lower 48 states" when he uncovered the bona fide, original punch recipe, purportedly "liberated" by a dinner guest from the State in Schuylkill clubhouse, known as the Castle, which sits on the Andalusia estate on the Delaware River's edge in Bensalem. He realized the recipe was something special when a bar owner offered him "a fortune" for it.

Now, D'Andrea's giving talks at exclusive clubs, contemplating a book, and bottling his original recipe in flasks, the price of which is available upon request. He's also trademarked the name Fish House Punch, and claimed the domain Fishhousepunch.com.

There's just one problem: It might not be the real original recipe, and the recipe itself might not even be secret. Club members, who still meet to this day, say there's no such thing as a secret punch recipe, and some are irked by the notion — but, fortunately for D'Andrea, they don't intend to come out of the shadows in order to shut him down.

Alfred Putnam, whose late father was once governor of State in Schuylkill, outright laughed at the idea.

"I would be very surprised if Fish House Punch was a secret," said Putnam, noting that his father had shared the formulation with the Inquirer in 1992 under no apparent duress.

"It's as old a cocktail as I know of, and of course it's quite deadly," he added. "If you ever have it at a party, you really have to warn people. They think it's lemonade."

A more closely guarded secret, supposedly, is the club's membership roster, though the club's officers can be found in the Social Register, a publication available to the masses at the Free Library. Charles Meredith III, listed as secretary in the 2017 Register, referred questions to Radcliffe Cheston, whom he identified as the current governor.

Cheston, who prefers to keep a low profile, nonetheless politely returned a phone call just hours before D'Andrea was scheduled to speak Aug. 16. He confirmed the punch is still served at Wednesday festivities at the Castle throughout the summer.

His initial reaction to learning of D'Andrea's spiel was one of pique.

"We decided it wasn't worth it to sue the guy. We don't have a copyright or anything," Cheston said. "I don't have any particular feelings about keeping the recipe a secret. I've shared it with friends. But that somebody would try to make money off of it is offensive to me."

"Some of our members are down there to confront him and expose him for the fraud he is," he added.

But as evening approached at the Metropolitan Club, the crowd, in seersucker and linen suits, appeared amiable.

Perhaps it was the calming effect of the punch, or the many caveats with which D'Andrea garnished it. He explained, after all, that he had no access to State secrets except for the one key find: a memo found in the archives of some midcentury American notable who had shared the purloined recipe with a friend as a sort of Christmas gift.

"I'd like to start off by positing a theory," D'Andrea told the crowd. "The best drinks and the best food all share a special ingredient and the ingredient they share is story."

Indeed, the story of the punch and of the Fish House where it was created is plenty spicy.

Created as the Colony in Schuylkill by a corps of Quaker gentlemen including the likes of Joseph Wharton and James Logan, the Fish House was an angling and eating club first situated on the Schuylkill banks, near Fairmount, and relocated several times. Today, its members still identify as "citizens," and its leader is "governor."

Recently, the club has retreated into obscurity, though a Daily News reporter stormed the Castle in 1992 (and was promptly ejected). The most recent account of a journalist who was allowed to linger there appears to be a 1905 New York Times article, describing meals cooked over an open fire by club members, with help from "apprentices," who may hold the position for five years before being admitted as members. According to the report, the punch there was served in a nine-gallon china bowl, an 1812 gift of East India merchant Captain Charles Ross, in which members' sons were supposedly baptized — in punch.

<< READ MORE: Phila. Fish House Punch Recipes: Take one part history…

Today, Cheston said, "there isn't much fishing done there." The tradition of the punch remains strong, though the recipe is adjusted, like any other, according to taste. "It's basically a citrus punch that has simple syrup, brandy, and rum in it, with a lot of lime juice and lemon juice," he said. "It's very potent."

That more or less matches the other recipes published over the years, including one dating, purportedly, to 1795 published in cocktail historian David Wondrich's 2010 book, Punch, and another, in Steven Grasse's Colonial Spirits, attributed to club governor William Camac in 1873.

D'Andrea argues that, while many recipes have been circulated, some are phonies and the rest are red herrings concocted by those who'd rather keep the formula to themselves.

He'd rather focus on the legend of the punch, including numerous poems devoted to its insidious intoxicating power. (A 19th-century favorite: "There's a place just out of town/ where if you go for lunch/ they'll make you forget your mother-in-law/ with a drink called Fish House Punch.")

Indeed, when a reader recipe was reprinted via the New York Times News Service in the 1970s, a slew of angry letters followed. "It is quite reprehensible to serve or publish the recipe for Fish House Punch without adequate warnings as to the effects on consumers," one griped. Another described a book club meeting that devolved into a raucous dance party. The police were called, but were served punch and ended up staying until 4 a.m. The writer added: "We have never tried it since."

Not all bartenders are fussy about authenticity. The Fish House Punch on the menu at Southwark takes the daring step of adding bourbon. Village Whiskey's version includes cognac, a blackstrap molasses-based rum, spiced sugar, peach brandy, lemon, and aromatic tea.

Paul MacDonald, the bartender at Friday Saturday Sunday, said he's occasionally made the punch, based on a recipe unearthed by cocktail historian Ted Haigh. It's not a favorite. "Taste in drinks has changed a lot since the 18th century," he noted. A key to his punch (and, he said, any credible bartender's), is oleo-saccharum, or sugar infused with the oil from citrus peels — a fussy step not mentioned in the versions shared by citizens.

He said he does not understand the recipe to be a secret. He'd be interested to see it — "as a historical curiosity" — but would not pay a fortune to do so.

"A lot of times punch recipes were developed as a way to mask poorly distilled spirits," noted Michael Alan, who researched the recipes for Colonial Spirits. "I think there would be a lot of variations on Fish House Punch, and all of them would be accurate. If it has brandy, rum, citrus, sugar, that's about all you need."

Back at the Metropolitan Club, which traditionally serves Fish House Punch at New Year's, members said the drink they're used to is both sweeter and weaker than the concoction D'Andrea was passing out. His brew appears a muddy brown, like the Schuylkill after a flood, and smells pretty much like a glass of straight rum.

Richard Meyer, who'd invited D'Andrea to give the talk, said he considered the recipe authentic "until proven otherwise. Who am I to argue?"

As for the Philadelphia contingent, if the men were there to confront D'Andrea, the punch seemed to have mellowed them.

"It's great fun," said Scott Jenkins of Villanova, shaking his head. "It's a great story."

Reached by phone afterward, Cheston said his members were appeased. "Their conclusion was, it was entertaining," he said, "but the punch was dreadful."