“This can no longer be ignored,” says Robert Downey Jr.’s Zodiac character, Paul Avery. He’s pointing at a pint-size Day-Glo blue cocktail sipped by costar Jake Gyllenhaal, who plays journalist Robert Graysmith, in David Fincher’s true crime thriller. “What is that you’re drinking?” Graysmith replies, “It’s an Aqua Velva.”

While calls for the 7&7 in Scorsese’s gangster films gave the whiskey highball a real-world popularity boost, and The Dude’s penchant for Kahlúa and cream in The Big Lebowski lent the White Russian a certain frat boy appeal, the same cannot be said for Graysmith’s Aqua Velva.

Few have heard of the drink today, and even fewer knew of its existence prior to the film’s 2007 premiere. Did the cocktail actually exist in the late 1960s era depicted on screen? Or was it simply a cinematic flourish?

In James Vanderbilt’s shooting script, delivered in late 2006, the Aqua Velva is entirely absent. Instead, the stage direction calls for a “huge blue umbrella drink,” later labeled as a “blue girly drink.” The drink is likewise nonexistent in the real Robert Graysmith’s 1986 book, Zodiac, which inspired the movie; nor in his 2021 release Shooting Zodiac, which details the making of the film. (Graysmith, now 79 and notoriously press-shy, did not respond to queries.)

Yet several online accounts, as well as books including Cocktails of the Movies: An Illustrated Guide to Cinematic Mixology, list the Aqua Velva as a legitimate cocktail—not a silver-screen fabrication. In most instances, it’s described as being made with vodka and/or gin, blue Curaçao and Sprite, a makeup that bears strong resemblance to the more ubiquitous Blue Lagoon and Electric Lemonade. Among all these references, however, not one can pin down the origin of the drink.

“At some point, probably the 1980s, someone created this cocktail in homage to the fragrance,” writes Difford’s Guide, referring to the “Ice Blue” aftershave that debuted in 1917. Though Simon Difford has been cataloging cocktail recipes since 1997, his Aqua Velva entry wasn’t added until January 2017, and he was unable to support his claims when pressed. Still, despite the uncertainty surrounding the drink’s origins, his recipe, like most others, cites Zodiac.

Indeed, most cocktail historians I spoke to had either not heard of the Aqua Velva, or simply don’t recall the drink existing prior to the release of the film. Even the Wikipedia entry for the cocktail was created in July 2007, three months after the film premiered.

Cocktails by the same name, however, occasionally appear in print before then. In July 1998, for example, The Vancouver Sun covered a hot new restaurant, Aqua Viva, which served a house Aqua Velva—a Martini with a dash of blue Curaçao. A couple years later and four provinces to the east, The Windsor Star published a recipe for the Aqua Velva that likewise resembled a Martini, with blue Curaçao standing in for vermouth. By January 2004, the Chicago Tribune published an Aqua Velva recipe that included tequila, blue Curaçao and “a secret blend of fruit juices,” garnished with a glow stick, which had reportedly been the most popular drink at the Artful Dodger nightclub the previous decade. Bar owner Brian Friedler claimed he and one of the house DJs improvised it on a particularly slow Sunday night.

Apart from their signature hue, little connects these recipes to the Sprite-topped creation widely accepted as the Aqua Velva of Zodiac fame. Since the exact recipe is never mentioned in the film nor its associated literature, it’s plausible that some bartender fabricated a recipe to fit the bill and—as often happens in the murky world of cocktail lore—it stuck.

We may never know who the mystery bartender is, but at least we know who to credit for its name. “I kept coming up with other names like ‘Blue Lagoon, Asia Blagoon’ for this drink to at least make it sound funny,” Downey told a Scottish newspaper in 2007.  “I think Jake Gyllenhaal came up with Aqua Velva.”