Indy 500 traditions, explained: Why does the Indianapolis 500 winner drink milk?

The Indianapolis 500 is one the strongest traditions in American sports.

From the 33-car field, to the singing of "Back Home Again in Indiana," to the releasing of balloons before the start of the race and the iconic Borg-Warner Trophy featuring the faces of past winners, the Indy 500 is rich with history and traditions. But perhaps one of the strangest traditions of the race is the winner chugging a bottle of chilled milk in victory lane.

It's a unique tradition that has appeared in every race since 1956, and has become a snapshot moment defining the elation of victory after winning one of the world's most iconic races.

MORE: How much money does the Indy 500 winner make?

Why does the Indianapolis 500 winner drink milk?

Celebrating an Indy 500 win with milk dates back to 1933 when Louis Meyer enjoyed a glass of buttermilk after winning his second Indy 500. Meyer's mother had always told him that the best thing to drink on a hot day was buttermilk. In 1936 when Meyer won again, he sipped his milk from a large glass bottle instead of a glass. An executive at what was then the Milk Foundation was so excited when he saw the photo of Meyer in Victory Lane in the next day's newspaper that he vowed to make the bottle of milk an Indy 500 staple.

The tradition was repeated for the next few years, but took a brief hiatus between 1946-1955 when milk was no longer offered at the speedway. The winner has had an ice cold bottle of milk every year since then. Today, all 33 drivers are polled before the race, asking for their of preference of whole, 2 percent or fat-free milk. Power listed no preference for his victory last year, and no one has been able to confirm what variety was given to him.

Why no buttermilk?

If the tradition began with buttermilk, why can't drivers choose that variety today? No, it's not a conspiracy from Big Dairy, but rather the American Dairy Association of Indiana looking out for drivers' taste buds. In a statement from Brooke Williams, director of communication for the American Dairy Association Indiana, to the Indy Star, the absence of buttermilk is the result of its new taste due to mass factory production. Buttermilk in the 30s was actually left over from making butter and was rich and creamy. Today's factory version is regular milk with a culture and salt added to it, creating a more sour tasting beverage.

As drivers continue to ask for buttermilk, however, Williams offered one possible caveat on the future of options: "(If) we see a driver drink a full glass of buttermilk before the race," Williams said, "we'll give them some special (consideration). For now, we're keeping it to the three options."

Who drank orange juice at the Indy 500?

The tradition of drinking milk was almost ended in 1993 by Emerson Fittipaldi. Following Fittipaldi's victory, he broke tradition by chugging a bottle of orange juice as several fans booed. Fittipaldi, an owner of a 500,000-acre Brazilian orange grove, quickly chased the OJ with the usual glass bottle of milk, but the American Dairy Association of Indiana was not pleased. Fittipaldi later issued an apology.

@darrenrovell Emerson Fittipaldi broke tradition & had orange juice (in a milk bottle). He was an orange grove owner. pic.twitter.com/rpHJHpYvx5

— John M. Bishop (@JohnBishop71) May 22, 2015

History of Indianapolis 500 winners

Three drivers —  A. J. Foyt, Al Unser Sr. and Rick Mears — have won the race a record of four times. Helio Castroneves leads all active drivers with three victories. The inaugural race in 1911 was won by Ray Harroun.