Shaken, not stirred, is a common refrain when ordering a Martini as if you were James Bond, though Martini purists might tell you that Bond got it wrong. Stanley Tucci whipped up his Negroni by giving it a shake, to the chagrin of many onlookers. People have feelings about shaking and stirring their drinks.

So what’s the hard-and-fast rule when it comes to giving a cocktail a shake or a stir? Basically, it comes down to this simple distinction.

When to Stir

“The rules for stirring versus shaking are actually quite simple,” says Deena Sayers, beverage strategist at Brown-Forman, one of the largest American-owned spirits and wine companies (with brands including Jack Daniel’s, Chambord, and Fords Gin). “Stirring will make a drink cold with less dilution from the ice. This is ideal for spirit-forward cocktails such as Old Fashioneds, Martinis, and Manhattans. As soon as you add anything like citrus, fresh juice, herbs, or spices to the recipe you’re going to shake it up, and shake it well.”

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A Definitive Guide to Shaken vs. Stirred Cocktails

Hard-and-fast rule: The boozier the drink and the fewer ingredients it has, the more likely it is that the drink should be stirred.

When to Shake

“I would say that the ‘rule’ is to shake cocktails that include juices, creams, syrups, and purees,” says Raven Johnson, chief mixologist for Pour Up Atlanta, a mobile bartending and catering company based in Georgia. “Shaking a cocktail also adds water back into the drink, diluting it, which is good in some cases!”

A Definitive Guide to Shaken vs. Stirred Cocktails

Among Johnson’s favorite shaken cocktails that prove the rule are the Margarita, Cosmo, and Mai Tai. A Margarita is also Sayers’s go-to shaken drink — though she mixes hers up by adding Chambord, jalapeño slices, and fresh lemon juice. ”Shaking this cocktail will not only extract the spice from the jalapeño slices,” she says, “but it will also aerate the lemon juice to give it a nice froth, and bind it to the rest of the ingredients — creating a silky-smooth texture which you would not be able to obtain by stirring.”

Beware of Bubbles

Johnson also points out that many “shaken” drinks are topped with carbonation. In these cases, the shake comes first, and the soda, tonic water, or other bubbly liquid (like Prosecco or beer), second. A general rule of thumb is to avoid shaking anything with carbonation — a classic rookie move. Or, as Johnson jokes, “can you say explosion?”