Frank Sinatra's Favorite Cocktail Only Requires 2 Ingredients

It goes without saying that celebrities can and often do have a massive impact on what's trendy, in terms of not just fashion but other categories as well — like, for instance, food and drink. One viral interview can have us all ordering a Negroni sbagliato with prosecco; a picture of an actress sipping an Aperol spritz at a press conference can make you start craving the warm weather tipple something fierce. Things actually weren't so different back in the 1960s, well before Instagram and Access Hollywood. If it caught on that a star had a favorite drink, the general public would follow suit out of curiosity, admiration, or whatever else it may be. And in the case of Frank Sinatra, that drink was a Rusty Nail.

Sinatra was the de facto leader of the Rat Pack, an informal group of actor-musicians that in the '60s had a reputation for debaucherous behavior, including a passion for drinking. And one drink Sinatra and his contemporaries would often be seen sipping is the Rusty Nail, a cocktail made of just two ingredients: Scotch and Drambuie. And while the Rusty Nail hasn't really been in fashion since the Rat Pack ran Hollywood, you never know when an old trend might resurface. If you're curious to try the drink that powered Vegas' best-known bad boys, by all means. You might find that you have a crooner's taste in drinks.

Drambuie: Scotch's little sister

The Rat Pack may have cemented the drink's popularity in the '60s and '70s, but it was originally designed for another artist by the name of Theodore Anderson at a Hawaiian bar in 1942, at least according to one legend. Others say it was invented in New York in 1937, only to disappear again until about the early 1960s, when bartenders at the swanky 21 Club in Manhattan re-introduced it to the scene. But given that Drambuie dates back to the mid-1700s, we imagine it's pretty likely that some Scotch distiller, at some point in time, thought to combine the finished liqueur with the base spirit it's made from.

If you've never had it, the taste of Drambuie is often described as spicy and sweet, with notes of anise and possibly fennel and rosemary. The actual ingredients are proprietary — according to the brand, only three people alive know the recipe — so you've really got to rely on your senses to understand what you're tasting. Again, if you're not a Scotch person, it might take a few sips (or glasses) to get accustomed to the taste. But if you're a Scotch lover, a drink that combines Scotch with more sweetened and spiced Scotch must be heaven.

Rusty Nail, hold the tetanus

The standard recipe for a Rusty Nail is about 2:1 parts Scotch to Drambuie, stirred and served in an Old Fashioned glass with ice and topped with some lemon zest and, sometimes, Angostura bitters. But it's not at all uncommon for bartenders to tweak the ratio in either direction, making it 4:1 Scotch to Drambuie to tone down the liqueur's sweetness, or even a 1:1 with equal parts of each for those who like their drinks sweet, or who may be unaccustomed to sipping whiskey straight. Of course, changing this ratio will change the taste and the strength of the drink, but know that in any case, this spicy-sweet, smokey, rich drink has a kick. Even the sweeter, less boozy versions are still going to be pretty strong, so even though it's considered an aperitif, you may want to be sure you have a little something in your stomach before you start imbibing.

As for the drink's name, its origins aren't clear, but it's likely a reference to the drink's "rusty," amber color — although one theory insists that it's because the drinks used to be, for reasons completely beyond our imagination, stirred with actual rusty nails. Let's hope that one is pure urban legend.