The Old-School Ingredient That's Missing From Your Cocktails

There are lots of recipes out there for deliciously creamy cocktails, usually made with ingredients like egg whites, heavy cream, and sugary liqueurs. But there's one thick, fermented dairy product that often gets left out of the cocktail conversation: buttermilk. Historically, buttermilk was a liquid byproduct of churning butter that became embraced as a shelf-stable dairy beverage due to its natural fermentation. Its acidic properties also make it a secret weapon for the perfect pancakes and killer biscuits. These days, we make buttermilk by culturing regular milk rather than churning butter, but it still has an old-fashioned charm and unique tangy flavor that could lend itself nicely to cocktails.

That said, you're unlikely to see many buttermilk cocktails on your standard bar menu these days. It's unclear if it was ever as popular a drink ingredient in Western cultures as, say, heavy cream, though TikTok user @happyhour.abby did find evidence of a buttermilk-based mocktail in a 1971 book of non-alcoholic drink recipes. Perhaps the most enduring drink made from buttermilk is chaas, an Indian beverage meant to aid in digestion and often seasoned with masala spices.

That's what expert mixologist Robert Lam-Burns, bar manager of LenLen in New York City, says he would model a buttermilk cocktail after. "If I was using buttermilk in a cocktail I'd probably go down the Indian chaas drink route — using chaas as the inspiration for a cocktail that includes spices, buttermilk, and various herbs," he said.

The combination of spirits and sour milk may sound dubious at first, but there are a number of ways to make it a winning one. Much for the same reasons buttermilk makes an unexpectedly great milkshake ingredient, its acidity adds complexity to sweet drinks and provides contrasting flavor notes of tangy freshness along with its creamy texture. "Buttermilk can be used as an interesting modifier in cocktails like flips — drinks that incorporate a whole egg — and clarified milk punches," Robert Lam-Burns suggested.

Like he explained, flips are drinks made with a whole egg (yolk and all), plus sugar and a fortified wine like sherry or brandy, though this is sometimes replaced with another spirit. Adding buttermilk to one of these cocktails would technically put it in the eggnog category, since those contain milk or cream. "Buttermilk would add acidity to creamy cocktails that otherwise wouldn't have any, like a Brandy Flip," Lam-Burns said. Many online flip recipes like to pair the sourness of buttermilk with the sweet, caramelized flavor of maple syrup or honey.

In addition to its acidity, buttermilk has clarifying properties. "Buttermilk does contain fat and protein, therefore it can be used as a clarifying agent when mixed with acid for cocktails," Lam-Burns said. Clarified cocktails use an agent like egg whites or milk to trap solid particles and impurities in a drink, which are then filtered out, leaving a remarkably smooth result. The intentional curdling and straining process gives clarified milk punches a clear color and pure taste through the magic of science.