‘Tis the season of long drinks—simple, sippable cocktails served over ice in a Collins glass (or, if you’re Derbying, something like this). One the easiest and arguably most satisfying long drinks is the Dark ‘n Stormy. A spicy, seductive ménage of just a few ingredients: dark rum, ginger beer, lime juice. Put ‘em all together and what do you got? A lawsuit.

No, seriously.

We thought we were as well versed in the particularities of Cocktail Law as anybody, so you can imagine our surprise to find out the Dark ‘n Stormy isn’t dark rum, ginger beer, and lime. In fact, there’s not actually any lime juice in the “authentic” recipe, just an option to rim the glass with a lime wedge. For the authentic recipe, you simply, forcibly combine 2 ounces of dark rum—Gosling’s Black Seal Dark Rum to be specific—and ginger beer. (So far as we know, you’re not legally bound to any particular brand of ginger beer, though Gosling’s did start making its own.) But yes, any other variation of the Dark ‘n Stormy with any other rum, even down to a spritz of lime juice, is technically illegal.

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We know what you’re thinking. Are the Cocktail Police going to bust down your apartment door and cuff you for using Appleton Estate or Bacardi? Probably not. But if you try to proliferate your off-brand Dark ‘n Stormy recipe on a large scale and/or for profit, you may get a phone call from a not-so-psyched lawyer. And that’s because Gosling’s has 5 live trademarks on file with the United States Patent and Trademark office. And they’re not just a formality.

“We defend that trademark vigorously,” E. Malcolm Gosling Jr. told The New York Times back in 2009. “[It] is a very time consuming and expensive thing.” Among the time consuming trademarks are everything from a kit for making Dark ‘n Stormys to merch (T-shirts, jackets, basically any and all Dark ‘n Stormy swag). Makes you wonder—in an industry where litigation over cocktail ingredients is a pretty rare (though not unheard of) event, why are the folks at Gosling’s making so many cameos in courtrooms?

Simplest answer we can think of: clinging to a successful invention. Gosling’s the company was born in Bermuda in 1806; the English family had originally been heading for America, but their charter expired, so Bermuda became home (not the worst Plan B). By the mid 1860s, Gosling’s had created their branded, robust dark rum—Black Seal (named after the black wax used to seal the top, not, as we had hopefully assumed, some awesome kind of Bermudan seal they kept as a pet). Story goes, sometime after WWI, a bunch of British soldiers on leave decided to mix that rum with homemade ginger beer, and the rest is history. Patented, heavily legally protected history. (As for the name, legend has it one of the British soldiers said the drink was “the colour of a cloud that only a fool or a dead man would sail under.” Cheery.)

British Army Bermuda
The British Army in Bermuda, 1916-1919, courtesy of Bermuda-Online.org

So Gosling’s got there first. And while yes, you can patent a recipe, the law, as always, is a little tricky and annoying here. According to the U.S. Patent and Trademark Office, you cannot patent a recipe if it can be considered “obvious.” But hey!, we’d argue, the Dark ‘n Stormy was the first instance of dark rum-meets-ginger beer in the whole universe! Again, per the shiftiness of U.S. patent law, “even if a previous version of a recipe cannot be found, a ‘new’ recipe could still be considered obvious.” So, while the Dark ‘n Stormy may not have the legal protections of a patent, they can protect the trademark of the Dark ‘n Stormy name, and what that means. And by “protect,” we mean sic lawyers on violators, anyone from Zaya rum (who tried to sub themselves into the recipe) to a blogger who simply suggested subbing in a cheaper rum (he tells of his thrilling “cease and desist” experience here).

Don’t freak out if you’ve made a “Dark ‘n Stormy” with Mount Gay or, god forbid, light rum. You’re not the only offender. Google “dark and stormy recipe” and you’ll find cocktail culprits from Rachel Ray to Esquire to The Today Show, all listing “dark rum” in their ingredients (though Esquire does say Gosling’s is “preferred,” they also say “anything dark and funky will work”). And they all get the lime thing wrong.

Looks like we’re all victims, and apparent perpetrators, of a delicious mix-up. Which, in a way, is the spirit of mixology and cocktails generally—the delicious, on-purpose mix-up. As Zaya rum put it, “by imposing a trademark or patent on a cocktail recipe one is suggesting to undermine a Mixologists’ artistic freedom.” We won’t get that heavy handed, but we get the point.

Considering the ubiquity of the drink, and the money and time they spend defending their trademarks, you’d think Gosling’s would just shrug and call it a day, take pride in the fact that they were there at the beginning and enjoy the success of the drink. But then, the drink is so wildly successful (it’s one of those cocktail classics you can safely get at almost any bar, no matter if its chic or dive) there’s serious financial incentive to holding onto ownership. “That’s a valuable asset we need to protect,” says Gosling, Jr.

Just to drive home the point, Gosling’s recently launched a canned version of the Dark n’ Stormy. Basically saying “this is so ours, we put it in a can.” Per their website, it’s “the genuine article,” an “authentic Dark ‘n Stormy cocktail so there’s zero compromise in taste.” Considering the slow conversion of all things booze to cans (and all things formerly canned to booze), maybe Gosling’s has the right idea.

And yes, in case you’re wondering, they’ve trademarked the canned stuff, too.