The Indy 500 tradition involving a bottle of milk being presented to the winner dates back to 1930s. Winner Louis Meyer celebrated his win with a bottle of buttermilk, following his mother’s advice of drinking the beverage on hot days. A dairy industry executive took that iconic image and ran with it, requesting milk be provided to all future winners. Eventually, and with some compensation involved, the tradition caught on and remains a beloved part of the race to this day.