When it comes to cocktails, there are few more traditional than the Old Fashioned. True to its name, the Old Fashioned cocktail is one of the oldest recorded recipes in the history of mixed drinks, developed in the late 19th century (this is way before the days of Don Draper and “Mad Men,” believe it or not).

Combining tradition with contemporary riffs, and competing histories with regional flare, the secret to this simple drink is in the details. From the size of the ice to the strength of the pour, here are eight more things you should know about the Old Fashioned.

It’s really old.

The Old Fashioned is one of the world’s first cocktails, dating back to around 1880. As the legend goes, James E. Pepper, master distiller of his namesake bourbon, introduced the world to the drink during a visit to the Waldorf Astoria Hotel in New York, where he often met with other American businessmen, such as John D. Rockefeller, Theodore Roosevelt, and Fred Pabst.

It’s easy as one, two, three (ingredients).

With only three ingredients, the Old Fashioned recipe is straightforward. Simply stir together bourbon or rye with simple syrup and Angostura bitters in a rocks glass, add your ice and garnish, and enjoy. It’s so easy, in fact, you can make it in less than 30 seconds.

It’s the official drink of a spirit-loving city.

Although evidence points to Pepper introducing the Old Fashioned to the Waldorf Astoria in NYC, others believe it originated in his hometown of Louisville, Ky. According to Louisville lore, the cocktail was invented in Pepper’s honor by a bartender at the Pendennis Club in Louisville. Louisville has gone a step further to claim the Old Fashioned as its own, naming it as the city’s official cocktail in 2015.

Oversized ice is vital to the Old Fashioned.

In Old Fashioneds, large ice cubes aren’t just for show: They’re science. Ice that has a larger surface area melts slower than small or crushed ice, ensuring that the drink won’t dilute as you drink it. And since the Old Fashioned is an alcohol-forward cocktail, avoiding dilution is key. Thus, oversized ice is a vital ingredient in the drink.

The garnish is (not) optional.

Experts agree that garnish choices can make or break an Old Fashioned. If you choose something too sweet, like a Maraschino cherry, your garnish will quickly overpower the cocktail, throwing off its balance. Instead, top the drink with citrus. A lemon-orange twist will elevate the cocktail, scenting the drink without overwhelming the palate.

The Old Fashioned is often reinvented.

For those looking to eschew tradition, the Old Fashioned can be modernized with various ingredients and techniques. Some of our favorite modifications include: The Carribean Old Fashioned Recipe — which uses two types of rum in place of whiskey, and adds tropical bitters for a summertime feel — and the Old Fashioned Summer Recipe, which subs whiskey for port, making for a low-ABV cocktail ideal for daytime drinking.

Old Fashioneds taste different in Wisconsin.

If you’re from the Northeast and order an Old Fashioned in the Midwest, you may be in for a surprise. That’s because in states like Wisconsin, bartenders often make Old Fashioneds with Korbel brandy and premixed “bug juice” — a combination of sugar, water, and Angostura bitters — instead of the classic whiskey, simple syrup, and Angostura bitters.

It hasn’t gone out of style, and probably never will.

The Old Fashioned remains one of the most popular drink orders in the world. In fact, it was named the No. 1 best-selling cocktail of 2020 by Drinks International. In a poll conducted by the publication, nearly 35 percent of participating bars named the drink as the most commonly ordered drink on the menu, and three-quarters placed it in their top 10.