The Whiskey Sour has had an easy time of it during the craft cocktail revival. Though it’s just as famous as the Martini, Manhattan and the Daiquiri, it’s largely been spared the intense debates that swirl around those cocktails. Instead, it was allowed to hang back from the fray and stay its dependable, easy-going self, rarely featured on hip menus, but always there should it be needed.

That isn’t to say, however, that the Whiskey Sour is a case that was long ago cracked. While it is a simple drink—merely whiskey, citrus and sugar—it poses, like any sour, several questions of construction that must be addressed.

To get to the bottom of it, a PUNCH panel of tasters sampled 17 versions of the drink, submitted by bartenders from across the country. Which whiskey should be used—bourbon, rye or something else? Do you serve it up or on the rocks? What ingredient proportions are best? And, perhaps most critically, egg white or no egg white? And, if there is an egg white, how should you shake the drink? Dry shake the egg white, then shake all else with ice? Dry shake everything, then wet shake? Reverse dry shake? The panel tasted all possible combinations of the above.

Though the history of the Whiskey Sour is discussed less frequently than that of other classics, it is one of the oldest of mixed drinks to have remained in regular circulation throughout the years. Mentions of it begin to appear in newspapers in the 1860s; a decade later it was fairly ubiquitous. After the repeal of Prohibition, it quickly rebounded to prominence, not just in its natural state, but in the form of bottled Whiskey Sours and in Whiskey Sour mixes. Commercial shortcuts like that helped to sully the drink’s reputation, as did the jettisoning of fresh juice in favor of sour mix. By the turn of the 21st century, the Whiskey Sour’s name was mud.

Modern bartending’s primary contribution to the Whiskey Sour’s current status (aside from bringing fresh juice back to the mix) was the return of egg white, an ingredient extra that, while not part of most early recipes, has come to be thought of in mixology circles as the “original” form of the drink. Order a Whiskey Sour in a craft cocktail bar today and, nine times out of ten, it will be an egg-white model. Indeed, of the 17 recipes submitted, 13 contained egg white.

The tasting’s two guest panelists, bartenders Tristan Willey (Booker & Dax, Long Island Bar) and Karen Fu (PDT, Donna), were split on their preferences regarding the egg white.

“It’s a good way to experience that texture and foam and mouthfeel that sours call for,” argued Fu. “It also tempers the whiskey.” Willey, meanwhile, prefers his Whiskey Sours sans egg white, but admitted their inclusion lent a visual snap to a drink that can otherwise have a dull appearance. “It’s really showy,” he says.

Regarding whiskey, both thought rye the stronger choice, as it carried more presence in the face of the flavor-subduing influence of the egg white. But each thought a high-proof bourbon could also do a stand-up job.

The judges were unswerving, meanwhile, in what ratios they thought resulted in the best Whiskey Sour: two ounces whiskey and three-quarter ounces each of lemon juice and simple syrup. Similarly, they both agreed that the preferred presentation is up and in a coupe, particularly if egg is part of the equation. “I think egg whites on the rocks are gross,” declared Willey. “They break down quickly.” Nevertheless, nearly half of the drinks submitted were served on the rocks, and many with an egg white.

In the end, the top three vote-getters all featured egg white and two solid ounces of whiskey. Dan Sabo of the Hotel Figueroa in Los Angeles took the top spot with his mix of two ounces Rittenhouse Rye 100, a half-ounce of rich simple syrup, egg white, one ounce lemon juice and the unorthodox injection of a half-ounce of orange juice. This take threw the panel (including me), which had agreed early on that it was “unquestionable” and “not even debatable” that lemon juice was the only suitable citrus in a classic Whiskey Sour. (A couple recipes that asked for lime juice were quickly 86’d during the first round of tasting.) The orange juice brought a subtle roundness and buoyancy to the flavor of the drink, as well a tiny boost of extra sweetness. Before learning of the orange juice’s inclusion, Fu had remarked that it was, “my favorite of the light-and-bright Whiskey Sours” in the contest.

In second place was Eric Adkins, of The Slanted Door and Hard Water in San Francisco. Composed of two ounces of Buffalo Trace straight bourbon, three-quarters of an ounce of lemon juice, an egg white and just one-half ounce of simple syrup, it was certainly on the tart side, but nonetheless balanced. “This is what you think of as a traditional Whiskey Sour,” said Fu.

Coming in third was Neal Bodenheimer, owner of Cure in New Orleans, who combined two ounces of Evan Williams Single Barrel Bourbon, a three-quarter ounce of lemon juice, a three-quarter ounce of simple syrup, an egg white and Angostura bitters served on the rocks. Despite its being served on the rocks with egg white, Willey still termed it, “very classic.”

The top three were among only four of the recipes that made it to the second round. This was a far smaller percentage than was the case in previous PUNCH tastings of Manhattans, Martinis, Negronis and Daiquiris—the latter the only other sour that has been put to the test. Fu had a theory as to why. “I think there are more combinations that can be made with the Daiquiri, in terms of sugar and rum,” she explained. “In the range we’ve seen with the Whiskey Sour, there are not as many drink deviations that are going to taste good.”

Given the apparently tight window for perfection allowed by the humble Whiskey Sour, then, perhaps it’s as worthy of careful execution as more revered drinks. It may not be called for often in the haute cocktail bars of Manhattan, but there are other bars in the world.

“When I go outside of New York,” said Willey. “I see ten times more Whiskey Sours ordered. I think it’s a go-to for a lot of people.”