Buttermilk

Why does the winner of the Indianapolis 500 drink milk in Victory Lane?

Three-time Indianapolis 500 winner Louis Meyer regularly drank buttermilk to refresh himself on a hot day and happened to drink some in Victory Lane as a matter of habit after winning the 1936 race. An executive with what was then the Milk Foundation was so elated when he saw the moment captured in a photograph in the sports section of his newspaper the following morning that he vowed to make sure it would be repeated in coming years. There was a period between 1947-55 when milk was apparently no longer offered, but the practice was revived in 1956 and has been a tradition ever since.
From Indy 500