As I’ve said before, Cocktail Codex , written by the key players at the famous Manhattan bar Death & Co., maintains that there are only six cocktails: the Old-Fashioned, the Martini, the Daiquiri, the Whisky Highball, the Sidecar, and the Flip. All others are simply variants on these “root recipes.” If you’ve never heard of the Flip—I certainly had not—its name derives from an obscure colonial practice I don’t feel the need to describe. It can be made in different ways, provided each way involves a whole egg. Egg whites are used in a number of cocktails, mainly for the sake of creating an appealing frothiness, but as far as I know, only the Flip mandates using the yolk as well. Here’s the Cocktail Codex recipe: 2 oz oloroso sherry 1/2 oz Demerara gum syrup 1 whole egg “Dry shake” these ingredients in a tin shaker (that is, without ice) to integrate the egg whites and yolk, then add ice and shake again to chill. Double strain into a small wine glass. Garnish with grated n...