Maybe you bought buttermilk to make some delicious scones.
Or perhaps you used half a bottle for some crispy fried chicken.
Either way, you’re probably here because you’ve found some old buttermilk and you’re wondering if it’s gone bad.
Here’s where it gets tricky: because of buttermilk’s tangy taste, it can be hard to tell if it’s gone bad. After all, we look for a sour odor and taste when regular milk has gone bad!
The good news?
Today, we’ll provide a failsafe guide to telling whether your buttermilk is off. What’s more, we’ll also cover the different types of buttermilk, how to store buttermilk, and how long it lasts.
TLDR: Buttermilk gets sourer and less buttery as it ages. You should always refrigerate your buttermilk, or freeze it for longer storage periods – up to 3 months!
Types of Buttermilk
First off, let’s cover the two types of buttermilk.
Cultured buttermilk is the type you probably have, as it’s what’s sold in the grocery store.
Cultured buttermilk is made by leaving bacterial cultures, salt, citric acid, and skimmed milk to ferment for 14-16 hours. This fermentation process allows live good bacteria to take over and converts the sugars in the milk to lactic acid.
Did you know? Lactic acid is what gives your buttermilk that delicious tangy flavor.
Your cultured buttermilk will have also undergone pasteurization, which is when it’s heated to 161 ° F (or 72 ° C) to kill bacteria. All buttermilk sold in the United States must be pasteurized.
Traditional buttermilk is the other kind of buttermilk. Instead of being the main product, it’s actually a byproduct of making butter. When fat is separated from culture butter, traditional buttermilk is the liquid that remains.
Traditional buttermilk has less lactic acid so it’s not as tangy, but it does boast super complex flavors. That’s why traditional buttermilk is preferred by most high-end restaurants.
How To Tell If Buttermilk Has Gone Off
It can be pretty hard to tell if buttermilk has gone bad, because it already has that sour flavor associated with bad milk.
Therefore, you should look for these signs instead:
- Chunkiness or bits
- A strong sour smell
If you want to try to tell if your buttermilk is off by taste, you should be trying to notice a sourer, less buttery flavor.
Let’s explore why. Remember that lactic acid we told you about? As buttermilk ages, it continues to sour. Buttermilk also contains a compound called diacetyl, which is what gives buttermilk its buttery flavor. Over time, the bacteria that create diacetyl decline, meaning the buttery flavor declines too.
How To Store Buttermilk
When it comes to storage, buttermilk plays by the dairy rulebook.
You should store your buttermilk in the refrigerator before it’s opened. Once you have cracked it open, reseal the original packaging, or transfer to an airtight container if necessary, before replacing in the refrigerator.
You can also freeze buttermilk, but it will noticeably change the texture and flavor. You’ll see separation once your buttermilk is thawed. Therefore, you should only use frozen-and-thawed buttermilk in baking, as, when used in recipes, you won’t notice the change in texture.
Transfer buttermilk to an airtight container, or use an ice cube wrapped in silver foil, to freeze. Remember: buttermilk will expand when frozen, so leave a little space in the container.
How Long Buttermilk Will Last
You can expect your buttermilk to last 7-14 days past its expiration date, provided you put it in your refrigerator as soon as you got home from the grocery store.
Once you’ve opened buttermilk, it will last for up to 14 days in the refrigerator. Use your common sense here – if you opened buttermilk 14 days past its expiration date, don’t expect it to be good for another two weeks after.
For long-term storage, you should really look to the freezer, or even opt for powdered buttermilk. In the freezer, your buttermilk will last for up to 3 months.
Buttermilk Storage: The Summary
Here are the key takeaways today:
- How to tell if buttermilk has gone bad: chunkiness, mold, sourer-than-normal taste or smell
- How to store buttermilk: in an airtight container in the refrigerator or freezer
- How long buttermilk lasts: up to 14 days in the refrigerator and up to 3 months in the freezer