Don’t underestimate buttermilk. This tangy shape-shifter has endured millennia of social and technological evolution and has emerged a culinary powerhouse many cooks can’t live or leaven without.
Contemporary buttermilk is a poster child for the importance of choosing ingredients with care. Whether you’re making buttermilk pancakes, flaky biscuits, or fried chicken, the buttermilk you choose makes a difference. Here’s how to find the best one for your cooking and baking needs.
What is buttermilk?
What many think of as buttermilk today is different from the versions used by previous generations. Old-fashioned buttermilk was an agricultural byproduct: When dairy farmers churned milk into butter, they collected the liquid runoff and called it buttermilk. It was fairly thin and would turn sour after a few days, thanks to naturally occurring bacteria and a lack of refrigeration. Historians believe some dairy farmers also used the term buttermilk to describe milk destined for the churn.
In the early 20th century, social and scientific developments transformed buttermilk, industrialized it, and brought it to the masses. In 1906, Nobel Prize–winning scientist Élie Metchnikoff of the Institut Pasteur popularized the idea that fermented milk products could promote longevity, turning what many in the U.S. called buttermilk into a health craze. Meanwhile, as waves of immigrants arrived from fermented-milk-drinking regions of Eastern Europe, the market continued to expand.
Across the U.S., dairy producers and food scientists met the moment. As the post-industrial age marched on, some dairy companies began using standardized bacterial starter cultures to ferment large quantities of milk quickly and economically. Those latter versions have the most in common with commercial, store-bought buttermilk.
Today, most producers make buttermilk by culturing cow’s milk with lactic acid–producing bacteria (such as Lactococcus lactis and Leuconostoc mesenteroides). The result is a tangy flavor, higher acidity, and thicker consistency than fresh milk, thanks to protein coagulation during fermentation. The fat content of the base product, however, can make a big difference. Buttermilk made from whole-fat milk has a creamier consistency than buttermilk made from skim milk. Yet, commercial low-fat buttermilk (often made with the low-fat milk leftover from heavy cream production) is likely easier to find at your supermarket, and is perfectly serviceable.
Reading labels is key. Some dairies use naturally occurring lactic acid bacteria to transform milk into buttermilk. But many brands mix stabilizers and thickeners, such as tapioca starch and carob gum, into their products for consistency. These will taste and behave differently in baking (more on that later).
What’s the best buttermilk for baking?
Cookbook author Cheryl Day calls herself a “buttermilk purist.” When she bakes, she uses cultured buttermilk made with nonhomogenized, additives-free whole milk. “It’s low-temperature, vat-pasteurized,” she says, and praises its rich mouthfeel. “I buy it from a local dairy with happy cows.”
Those details make all the difference. Commercial cultured buttermilks with lower fat and additives don’t have that “rich, pure flavor,” Day says. “There’s a certain taste that you want, especially with something as simple as a biscuit or a yellow cake. When you add a bunch of stuff, it’s almost like overcompensating for the flavor you’re not getting.”
Baking is essentially the world’s most delicious chemical reaction, and buttermilk is prized for how its acidity interacts with alkaline leaveners like baking soda. The reaction produces carbon dioxide, helping cakes, waffles, and biscuits rise. Using lower-fat buttermilk with additives affects how baked goods spread and brown. “It changes the texture,” Day says.
Renata Ameni agrees. The executive pastry chef and partner at Birdee in Brooklyn, New York, uses slow-cultured buttermilk from local dairy Ronnybrook to make the bakery’s chocolate and red velvet cakes, as well as a buttermilk panna cotta. “It makes cakes more tender,” she says. “Even if you’re not baking it, like in the panna cotta, you can tell.”
Buttermilk in savory cooking
Buttermilk adds tang and acidity to mashed potatoes, makes salad dressings (like homemade ranch) creamy, and adds moisture to buttermilk biscuits and cornbread.
In parts of the American South, buttermilk is enjoyed as a beverage. Some cooks pour it over toasted day-old cornbread to eat like cereal.
It’s especially effective as a marinade. In recipes for fried chicken, country-fried steak, and more, the lactic acid in buttermilk gently denatures proteins, reshaping their collagen structures and increasing moisture retention without turning the meat mushy. As a result, buttermilk-marinated meats cook up tender, tasty, and extra-juicy.
What’s a good substitute for buttermilk?
While many argue there is no substitute for buttermilk, you can swap in kefir or stir water or whole milk into plain yogurt until it reaches buttermilk-adjacent consistency. In a pinch, Day has thinned sour cream with water.
If you want something with a longer shelf life than traditional buttermilk, buttermilk powder is another option to keep on-hand for its tangy, cheesy flavor. Powdered buttermilk can hide out in your pantry for months or even years if kept dry. Use the powder to add oomph to popcorn, tang to poultry marinades, or to swish into pasta, or reconstitute it with water to use like regular buttermilk.
Some bakers find that adding lemon juice or vinegar to milk approximates buttermilk’s acidity adequately for their uses. But, because this common internet hack lacks the flavor, thickness, and baking prowess of cultured buttermilk, many professionals don’t recommend it.
Instead, consider keeping reserves on hand. “Buttermilk freezes beautifully,” says Day. She suggests keeping extra in ice cube trays or freezer bags until you’re ready to defrost and use it. “The texture does get a little grainy, it does look a little different, but it doesn’t seem to affect how it performs or tastes when you bake with it.” As always, buttermilk endures.
