A writer walks into a bar. It sounds like the beginning of a joke, but when it happened at the Buena Vista on November 10, 1952, a new drink was born. Stanton Delaplane, a longtime columnist for the San Francisco Chronicle, walked in on that chilly November day and told the bar owner, Jack Koeppler, about a warm whiskey-and-coffee concoction he’d tasted in Shannon, Ireland. The oft-told story goes that the two men spent the evening measuring and mixing and testing in an effort to re-create the drink. Eventually, the recipe was mastered, and seven decades later, the Buena Vista’s Irish coffee is as legendary as San Francisco fog. Bartenders in crisp white jackets line up glass goblets on the bar and make up to 2,000 Irish coffees per day.