In one of the most iconic lines from Hollywood, James Bond requests his martini to be shaken, not stirred. As alluring as Bond, James Bond is, he makes a better spy than bartender. If you want to wow your guests and boost your bartending reputation, here are a few tips from our friends at Marlow’s Tavern to help you understand when to shake and when to stir.

Cocktails that are served shaken are typically complex drinks made with more than two ingredients. Imagine the classic cocktail, Planter’s Punch: a deliciously complex mixture of rum, citrus, sugar and spice. Cocktails such as these are shaken in order to blend the drink’s ingredients together smoothly so each sip tastes the same.

If a drink has citrus in it, you shake it. If you’re making a whiskey sour or pink lady, which both use egg whites, you shake it. If you’re making drinks that use cream or half and half, like a brandy Alexander or white Russian, you shake. The purpose of shaking these cocktails is to incorporate air bubbles, which produces a drink that is light and frothy.

Generally speaking, if a drink is made with all spirits, it’s stirred, not shaken. Spirits refer to unsweetened, distilled alcoholic beverages: vodka, gin, brandy, whiskey and tequila. Spirits, for the most part, are equal in density, so all you need to properly combine them is a spoon. Drinks like martinis, Manhattans and old fashioneds are made with all spirits.

Never Say Never Again
If you’re looking for a scientific reason to shake a martini, University of Florida chemist George Christou claims that shaking does a better job of removing volatile organic compounds from the alcohol. Air oxidizes other organic compounds that may be present, affecting the taste. It’s similar to allowing red wine to breathe before serving. Christou also says some cheaper vodkas made from potatoes have some oil in them, and shaking will make an emulsion that will hide the oily taste.