I drank White Russians recently with a friend who is an experienced bartender and bar manager recently and he said they always have Kahlua and milk around. People order strange things but there’s shots that include both that people order more than you’d think.

He basically said that they make sure they have all the ingredients but adjust quantity for the expected crowd. He works at a music venue nowadays and after awhile, you know what drinks are gonna get ordered based on the band’s core audience. But they’d send a bar back out to get more milk at the corner store if someone was a regular or spending money.