What Is Buttermilk — and How to Use It

Buttermilk is a versatile ingredient that can add lift to baked goods for the fluffiest pancakes, waffles, and biscuits, tenderize chicken and other proteins, give rich texture and tangy flavor to dressings, and shine in delicate desserts like buttermilk panna cotta. No matter where you might want to add oomph to your cooking, buttermilk can help. Here’s everything you need to know about buttermilk, and how to use it.

What is buttermilk?

Traditional buttermilk is the fermented, low-fat liquid byproduct of making butter. Beating or churning cream solidifies the fat in to create butter, and the liquid that is leftover is buttermilk. Back in the day, buttermilk would be left out to ferment, and bacteria would produce lactic acid that would give it its signature slightly sour flavor. These days, the buttermilk you buy at the store is cultured buttermilk, made from cow’s milk that’s been made in a more controlled way, similar to how yogurt is made: Live cultures are added to skim or whole milk to ferment it. Cultured buttermilk is thicker than heavy cream with some small tender lumps, a rich, pale, golden color, and a pleasingly tangy flavor and aroma. 

Buttermilk is also an acidic ingredient (The pH of buttermilk is around 4, while cow’s milk, a more alkaline ingredient, is close to 7). This gives it its vibrant, tangy flavor, and also helps it to break down and tenderize the tougher fibers of protein.  Buttermilk is also a good emulsifier, helping to stabilize sauces, dressings, and creams. 

How to store buttermilk

According to the USDA, buttermilk can be safely kept in the refrigerator for about two weeks. If you want to keep it much longer than that, you can also freeze it. Food & Wine associate editorial director Chandra Ram likes to freeze her buttermilk in half-cup portions for easy use. (Be sure that before you freeze buttermilk, it still smells fresh, and has no off-odors or visible contamination.) Buttermilk can be stored frozen for up to three months.

How to use buttermilk

Fermented dairy, including buttermilk, kefir, and yogurt-based drinks have been imbibed in many Middle Eastern, Arab, and Indian countries for centuries. Some Germanic and Nordic countries also keep buttermilk in their household to enjoy as a beverage, and it was once more commonly consumed as a drink in the United States, especially in the South. Today, drinking buttermilk is less common in the U.S., where it is more often used in baking, desserts, and savory cooking.

Baking with buttermilk

Quick breads and pancakes get a real lift from buttermilk. Not only does it deepen the flavor of your bake, but the acid in the buttermilk works with leaveners like baking soda to give it a fluffier interior crumb and more rise. However, it does not react the same way with baking powder. Because of the higher acid, buttermilk actually inhibits the leavening process by reducing the amount of carbon dioxide released if used in concert with baking powder. F&W associate food editor Paige Grandjean advises, “For recipes swapping milk for buttermilk, be sure to reduce the amount of baking powder by half and add 1/2 teaspoon of baking soda for every 1 cup of buttermilk.”

Try buttermilk in cakes, crumpets,  old-fashioned doughnuts, cornbread, or in Irish soda bread. Buttermilk is also great for making desserts, giving them a more nuanced flavor profile. Try making buttermilk granita, coconut-buttermilk pie, and panna cotta, or use buttermilk to enhance the taste of your next batch of whipped cream or ice cream. 

Cooking with buttermilk

Thanks to its acidity, buttermilk is a great tenderizer. It’s the classic soak for fried chicken, and you can also use buttermilk for dredging that chicken before breading and frying it. The buttermilk will help the flour mixture adhere to the meat, add flavor, and make it even more tender. Buttermilk can also be used in place of a brine. Try flavoring the buttermilk with your favorite herbs and spices, and let your poultry or pork chop take a buttermilk bath.

Buttermilk can offer tang and brightness to everything from a creamy salad dressing to soups a whole new dimension. It can be used in place of milk in a bolognese sauce or to bump up the flavor of marinara. “My mom used to throw a little vinegar into her turkey and chicken stews to brighten them up; I do the same with buttermilk,” says F&W executive editor Karen Shimizu.  Buttermilk brings unexpected brightness to a  poblano chile-laced gravy, and can add a pleasant tang to macaroni and cheese or to mashed potatoes.

Selecting a buttermilk substitute

If you don't have buttermilk, you can approximate its tang, lift, and moisture in baking by thinning whole plain yogurt with an equal amount of water. Kefir, a fermented dairy product which is made by fermenting milk with a culture of bacteria and yeasts, can also be used in place of buttermilk in recipes. Another workaround if you don’t have buttermilk is to make clabbered milk by adding one tablespoon of an acidic ingredient like vinegar or lemon juice to a scant cup of milk or cream. 

An even better substitute for buttermilk is buttermilk powder. Buttermilk powder is buttermilk that has been dehydrated until it becomes a fine powder, similar in texture to flour. To use it, mix a tablespoon of buttermilk powder into a cup of water, and use it as you would liquid buttermilk. 

So, the next time you’re hesitating over whether to pick up a carton of buttermilk at the store, go for it — and know that the next time your cooking needs a boost, all you need is a splash of buttermilk.