If you go to Churchill Downs in Louisville, Kentucky, on the first Saturday in May, you're bound to notice two things about those in attendance. The first is that almost every single one of them will be wearing a fabulous hat. The second is that many of them will be drinking a mint julep.
The Kentucky Derby website reports that almost 120,000 of the bourbon-based cocktails are served during Kentucky Derby festivities. Traditionally, the drink is made with bourbon, sugar and muddled fresh mint with more mint as a garnish. To make it possible to serve such a large group of people in such a short time, bartenders currently use Old Forester Mint Julep, a bourbon infused with mint specifically for the Kentucky Derby. They also go through 1,000 pounds of fresh mint for garnish and about 60,000 pounds of crushed ice to create the official drink.
Why did the drink become the horse race's official cocktail? The short answer is to stop people from stealing glasses.
The mint julep already had a history with the Derby before it became the official drink in 1939, as CNN reports. A bourbon-based cocktail is a natural fit for a Kentucky sporting event; the state prides itself on its bourbon. It's also a refreshing cocktail with a good amount of ice, cooling off Derby attendees in the heat of the day.
The first mention of the drink being associated with the Derby is from 1877, when Polish actress Helena Modjeska kept a large mint julep intended for a group to drink all to herself and then ordered a second. The cocktail also got some press when Prohibition hit. Journalists wrote about the lack of availability of mint juleps for both the crowd and themselves at the Kentucky Derby.
It wasn't until after Prohibition that the drink became official, and the decision to make it so had to do with the glasses the cocktail came in. The racetrack managers discovered that people were stealing the julep glasses, sneaking them out of Churchill Downs as souvenirs. In 1940, the first official Kentucky Derby Mint Julep glass was made and sold as a souvenir. Since then, a different glass has been created annually, and the glasses have become collector's items. The front of the glass has a new design each year, and the back of the glass lists all of the winners from the race's history.
Now, the price of the glass is built into the drink, and people are welcome to walk out of the racetrack with their souvenir glasses. Even those who don't go to the racetrack on Derby Day can get the souvenir glasses. The derby's official website sells the 2019 officially licensed 12-ounce mint julep glass for $5.99. Of course, if you order a bunch of glasses for your own Derby Day party, you may want to be prepared for guests to sneak a glass or two home as a souvenir.