How Long Does Buttermilk Last?

Buttermilk is a popular addition to recipes like pancakes, biscuits, cakes, pastries, and cookies for added moisture and flavor. With its signature tangy taste, it may be hard to determine if buttermilk has gone bad, so you may find yourself wondering – how long does is actually last?

Just like all dairy products purchased from the grocery store, buttermilk has a shelf-life. We reached out to an expert for advice and storage tips.

What Is Buttermilk?

Historically and traditionally, buttermilk was the liquid left after churning cream into butter. This liquid was left to ferment in root cellars, which made it tangy and thick. 

“Today, buttermilk is cultured, meaning a live lactic bacteria culture is added to pasteurized milk to cause fermentation, giving its tangy characteristic and thick consistency,” Vickers explains.

How Long Does Buttermilk Last?

Two weeks past the stamped ‘sell by’ or one week past the ‘use by’ date, especially when unopened and kept refrigerated,” says Vickers.

How To Tell If Buttermilk Has Gone Bad

Vickers says there  are some distinct indicators to tell if buttermilk has gone bad, including:

• How does it smell?Buttermilk has a naturally fresh, tangy smell – a slight vinegar smell – but, if it smells sour (like regular whole milk might), it’s likely spoiled.
• Do you see any mold? Any visible mold on the surface is a clear indicator that it is no longer safe to consume.
• Has the liquid separated? If the liquid and solids of the buttermilk have completely separated – and the liquid is very water – it may be spoiled.
• How does it taste? Buttermilk tastes similar to plain yogurt; therefore, if it tastes off or unpleasant, it is best to discard it.

What Is The Best Way To Store Buttermilk?

Buttermilk should always be stored in a refrigerator at or below 40 degrees Fahrenheit. 

“Because storing dairy products in the door of the refrigerator can cause them to spoil quicker due to the rapid temperature changes every time you open the door, I recommend placing the carton on a shelf inside of the refrigerator,” Vickers says. “I also recommend placing buttermilk into a container you can seal tightly because it can absorb the odors of your refrigerator.”

Can You Freeze Buttermilk?

Yes! If your buttermilk looks like it's about to go bad, it can be frozen. 

“I like to freeze buttermilk in ice trays and then place them into a Ziploc bag to use in my recipes at a later time,” Vickers says. “One may think that after being thawed, buttermilk will separate and have a different texture, however, it is still suitable for cooking and baking because we just want the moisture and flavor from it.

What Can You Substitute For Buttermilk?

If you are in the middle of a recipe and realize there isn’t an ounce of buttermilk in the house, don’t panic. Vickers says this has happened to her, too, and there’s an easy solution. 

“There have been times when I had no frozen cubes in the freezer and I was in the middle of mixing a recipe and needed buttermilk,” she explains. “I simply substituted for it by adding one tablespoon of vinegar or lemon juice to one cup of milk, and then let it sit for about five to ten minutes or until it thickens slightly.