What Is Buttermilk?

A Guide to Buying and Cooking With Buttermilk


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The name "buttermilk" suggests a buttery, high-fat milk, but this couldn't be further from the truth. Buttermilk contains no butter, and it's actually lower in fat than regular milk. The "butter" in the word buttermilk refers to the origins of this versatile fermented beverage, which resulted from the process of churning butter. Buttermilk adds tangy flavor and creamy richness to dishes from savory to sweet, and powers the leavening in baked goods.

Fast Facts

  • Calcium: 1 serving contains 22% DVA
  • Shelf Life: 1 to 2 weeks for fresh buttermilk; up to 2 years for powdered
  • Substitute: 1 tablespoon lemon juice or white vinegar plus milk to equal 1 cup

Cultured vs. Churned Buttermilk

The buttermilk you find in the grocery store refrigerator case differs from the buttermilk your grandmother used. Nowadays, most buttermilk comes from an industrial process more similar to yogurt-making than churning butter. Bacteria cultures are added to pasteurized low-fat or skim milk, which is left to ferment for 12 to 14 hours at a low temperature (optimally 69 degrees Fahrenheit). Salt, stabilizers, and sugar may also be added. This type of buttermilk is usually labeled "cultured buttermilk."

Old-fashioned homemade buttermilk is the slightly sweet liquid that remains after butter is churned. It may be flecked with tiny spots of sweet, creamy butter that didn't quite make it to the top to be skimmed. It takes 1 gallon of heavy cream to yield 1/2 pint of true buttermilk.

In either case, fermentation converts the milk sugars into lactic acid, which is what makes buttermilk so desirable for baking and gives it that signature tangy taste. The lactic acid also inhibits the growth of dangerous bacteria, allowing for longer storage. Commercial buttermilk is more acidic, thicker, and tangier than the old-fashioned version. Store-bought buttermilk actually works better for baking when recipes include baking soda; it works with the buttermilk to provide the leavening and reduces the buttermilk's acidity.

Buttermilk Uses

Buttermilk was prized by older generations for its slightly sour flavor and remarkable properties in baking. When paired with baking soda, as it is in recipes such as buttermilk pancakes and buttermilk biscuits, the buttermilk's lactic acid reacts vigorously, creating a great rise and exceptional crumb. In addition, the lactic acid can be used to tenderize meats, as it is often called upon to do in fried chicken recipes. It's a staple in salad dressings, dips, and Southern pies.

How to Cook With Buttermilk

Buttermilk curdles if you heat it too quickly. To incorporate it into soups and other hot dishes, warm the buttermilk separately in a sauce pan over medium low heat first.

Recipes With Buttermilk

Southern cooks love their buttermilk and depend on it to add flavor and texture to all types of dishes.


Traditional Southern Buttermilk Cornbread Recipe

What Does It Taste Like?

The flavor of buttermilk is reminiscent of yogurt and most people prefer it well-chilled. You will find it to be slightly thicker in texture than regular milk but not as heavy as cream. It adds a distinctive tang to pancakes and baked goods.

Buttermilk Substitute

You can add an acid to milk and use it in place of buttermilk in many baked goods. Measure 1 tablespoon of lemon juice or white vinegar into a liquid measuring cup, then fill it to the 1-cup mark with milk. Stir well, let it stand for 5 minutes, then use the amount called for in your recipe. Cream of tartar dissolved in milk also works; use 1 3/4 teaspoons per cup of milk. Otherwise, thin yogurt with milk or sour cream with water until it reaches the right consistency and substitute it 1:1.

Where to Buy Buttermilk

You can purchase mass-produced buttermilk at nearly any supermarket but you are likely to find better quality buttermilk at small natural foods stores or direct from local dairies. It's nearly impossible to find true old-fashioned buttermilk, but you could churn some butter and make your own. Look for shelf-stable powdered buttermilk in the baking aisle.


Buttermilk lasts longer in the refrigerator than other dairy products. Generally, it's safe to use for two weeks past the sell-by date. The solids may separate from the liquid, but give it a good shake until it comes back together. Buttermilk also freezes well; pour it into portioned containers or by the tablespoon in ice trays and use it within three months. Thaw it in the fridge or on a low setting in the microwave. Stored properly, powdered buttermilk can last for years.

Article Sources
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  2. CFR - Code of Federal Regulations Title 21.” Accessdata.fda.gov, www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=131.112.

  3. Mokoena MP. Lactic acid bacteria and their bacteriocins: classification, biosynthesis and applications against uropathogens: a mini-reviewMolecules. 2017;22(8):1255. doi:10.3390/molecules22081255