The mint julep is the official drink of the Kentucky Derby—but the cocktail's history dates to back long before the famous event was even conceptualized.

The Ancient (and Medicinal) Origins of the Julep

According to David Wondrich's cocktail history book Imbibe!, the first known record of a julep is from the Kitab al-Mansuri, a Persian medical text dated to around 900 CE. However, the julep that the author included in the Kitab al-Mansuri looked much different than the modern favorite (it was also written as julāb). It was a medicinal drink made by soaking violets with sugar in water. "Julep" pops up in the historical record again in the 1400s when the book was translated into Latin.

The drink was used almost strictly as medicine for centuries. It migrated across the Atlantic with early European settlers making their way to America, along with an herb prized for its medicinal qualities: mint.

Why the Mint Julep is a Spring and Summer Drink

Around the time the julep hit the U.S., things changed a bit. In the 18th century, people started drinking it recreationally as well as medicinally, but we wouldn’t recognize those tipples as a modern julep.

First off, they would have been made with whatever spirit was locally available. Before the Civil War, Southern juleps were likely made with fruit brandy. In Maryland, the julep was (and still is) made with rye whiskey. Elsewhere, it would have been made with rum or rye or moonshine or pretty much any available booze. The drink would be sweetened with honey, sorghum syrup, or any other available sweetener.

And since mint wasn’t available year-round—it’s a perennial plant that grows near water, and, according to The Kitchn, pops up first thing in the spring—the mint julep would have been a seasonal drink, best enjoyed in the spring and summer.

Kentucky Senator Henry Clay: Inventor of the Mint Julep

Henry Clay: American statesman, Speaker of the House of Representatives, and inventor of the mint julepHulton Archive/Getty Images

As the story goes, bourbon’s role as the go-to base for the julep was cemented by Kentucky Senator Henry Clay. Clay is famous for a number of things, such as brokering the “corrupt bargain” that secured the 1824 presidential election for John Quincy Adams. The Kentucky senator also mixed his mint juleps with his state’s native spirit, and he is credited as the bourbon mint julep's founding father.

Clay’s love of the julep is well-documented. He likely introduced the drink to the famed Willard Hotel in Washington, D.C. around the time it opened in 1847. Clay's journals indicate that he made his juleps with “mellow bourbon, aged in oaken barrels.”

Henry Clay’s Mint Julep Recipe

As collected by the University of Kentucky Press, Clay's mint julep recipe from his diary is as follows:

"The mint leaves, fresh and tender, should be pressed against a coin-silver goblet with the back of a silver spoon. Only bruise the leaves gently and then remove them from the goblet. Half fill with cracked ice. Mellow bourbon, aged in oaken barrels, is poured from the jigger and allowed to slide slowly through the cracked ice.

In another receptacle, granulated sugar is slowly mixed into chilled limestone water to make a silvery mixture as smooth as some rare Egyptian oil, then poured on top of the ice. While beads of moisture gather on the burnished exterior of the silver goblet, garnish the brim of the goblet with the choicest sprigs of mint."

Or, in modern terms:

Handful of mint leaves
1/4 to 1/2 ounce simple syrup
3 ounces bourbon
Crushed ice

Lightly press (don’t smush!) the mint leaves against the inside of a silver julep cup so that you can smell the mint. Add the simple syrup. Fill the glass halfway with cracked ice, and pour the bourbon over the ice. Stir until the glass starts to frost over. Add more ice and stir again. Garnish with a mint sprig and serve with a short straw.

Why do people drink mint juleps at the Kentucky Derby?

The mint julep has been the official drink of the Kentucky Derby since the 1930s.Jason Kempin/Getty Images for Churchill Downs

Mint juleps have been served at Churchill Downs—the home of the Kentucky Derby—since the track was built in 1875 (legend has it that mint was even planted at the track for juleps). But the mint julep didn’t become the official drink of the Derby until the 1930s. Sarah Brown Meehan, director of lifestyle communications at Churchill Downs, told Good Morning America that "we know that juleps were a big part of the event by Prohibition because the press at the time lamented the Kentucky Derby without its favorite drink."

After Prohibition was repealed, master bourbon distiller Chris Morris told GMA, making juleps the official drink of the Derby “simply recognized the fact that Kentuckians had been enjoying mint juleps while attending horse races since the early 19th century, if not earlier."