How To Tell If Buttermilk Is Bad – When Does It Spoil?

There are several ways to determine if your buttermilk is bad. Sniff the buttermilk, look at the texture, take a tasting, or look at when it expires. If something seems odd there’s a good possibility that the buttermilk has been spoiled. If in doubt, chuck it out!

Buttermilk is widely used in baking, and it gives baked goods a slight tart flavor. Buttermilk is the liquid that runs off produced by churning butter. It is now a food product that is cultured that is rich with probiotics as well as calcium potassium, and Phosphorus.

Because it is typically utilized in baking but rarely used for other purposes it is usually stored within the fridge for a lengthy period of time.

It can be difficult to determine if buttermilk is bad, particularly when you’re not used to it at home, since it has a different texture than milk. It also has a distinct smell, something that we all think of as off milk. Here is all you need to know about how to determine if buttermilk is bad, the reasons why buttermilk could go bad, and ways to extend the shelf life of your buttermilk.

Easy Ways To Tell If Buttermilk Is Spoiled

There are several indicators you can look out for to determine whether buttermilk is off or not. So if you’re not certain whether it’s in fact of it is, look for additional signs before making an informed choice.

By using the various senses There are several indicators to identify if buttermilk is spoiled.


Buttermilk has a slightly stronger tangy scent than normal milk, or any other dairy product, however, the scent tends to get sourer as the product ages.

There’s a time in the storage of buttermilk that it is difficult to identify a distinct foul smell. However, when it is properly so, you’ll be able to recognize it immediately.

Be aware that a sealed carton of buttermilk will emit an odor that is stronger because the smell hasn’t had an opportunity to go away and so take this into consideration when smelling a freshly opened carton of buttermilk.

Buttermilk will retain a buttery, scent, but it shouldn’t be too sour.


It is easy to determine the extent to which buttermilk is gone by just taking a look. As it ages it can show minor discoloration.

Buttermilk that is past the expiry date could be contaminated by mold that has grown on the surface or within the lid. This is due to the increase in bacteria, and if there is mold in the buttermilk, or on the container, eliminate it immediately It isn’t worth any food-borne illness that comes when you drink buttermilk containing bacteria.


The best way to determine whether buttermilk is spoiled is to check the texture (and touch it if willing to risk it).

When it starts to become bad, buttermilk forms the appearance of clumps and thickness. It can be difficult to pour, and there are massive chunks of clots. It is impossible to get buttermilk back that has become a lump since there is a possibility that it has been spoilt.

It is important to note that buttermilk can naturally contain a few lumps. This shouldn’t interfere with how the buttermilk is poured. small clumps of it should be broken up as it is whisked, and when mixed alongside other elements.


You may have missed the other indicators that buttermilk might be out of whack, and the taste could be the next thing to consider.

Buttermilk can have an astringent taste however, if the buttermilk is sour or off in any way, it must be thrown out.

Buttermilk must also be a bit buttery in taste, with a certain creaminess. This goes away once the buttermilk begins to go through the process of spoiling.

Expiration Date

The best way to know if your buttermilk has gone bad in the event that you aren’t sure whether you are looking at other indicators is to examine the date of expiration.

If you are unable to discern if the product is not right through tasting, smelling, and inspecting the texture and it’s not past when the date of expiration is, it will be safe to use.

But, if it is one week after when the date expires, it is best to throw away this buttermilk.

The Reason Why Buttermilk Spoils

As with all dairy products the buttermilk eventually spoils. Buttermilk is rich in lactic acid which can be a threat to the growth of harmful bacteria, but this won’t stay for long, and after some time, the harmful bacteria start to multiply as the milk continues to ferment, and it becomes increasingly acidic.

The growth of the bacteria causes the buttermilk to go bad and makes it unsafe to drink after the expiration date, as it is more likely to be the cause of getting food-borne illnesses.

How Much Time Does Buttermilk Last?

Each buttermilk product will have an expiry date and sell-by date. It is vital to keep in mind it is possible to be able to utilize the buttermilk one week after the date of sell-by however, this depends on the way you stored the milk and how it is moved.

When the container of buttermilk is open, the degrading of the product accelerates. It is recommended to use up a bottle of buttermilk within one or two weeks of the time it is opened.

Again, this is dependent on the quality of the buttermilk that is stored as well as if it is contaminated by other products.

No matter if it’s opened or unopened buttermilk should be stored in the refrigerator.

Tips: If you’d prefer buttermilk that lasts longer and doesn’t have to be stored in the refrigerator, then it is recommended to use powdered buttermilk. This is the one that my mom always used when I was growing up.

How To Increase The Shelf Life of Buttermilk

Buttermilk should be in a refrigerated place and not allowed for a long period of time at temperatures of room temperature. If you do not plan to use the buttermilk right in the near future, it is better to keep it unopened. An unopened carton of buttermilk is unlikely to last for as long as one that has been kept not opened.

Use good hygiene when handling the buttermilk. make sure your fingers stay far from the cover while you pour it out and don’t drink straight out of the carton since this could introduce bacteria into the buttermilk that could cause it to spoil more quickly.

I would also recommend using it in a high-quality Airtight container to store your buttermilk that will make it keep its shelf life longer.

Also, you have the possibility to store buttermilk in a freezer to prolong the shelf life. Freezing will alter the consistency slightly and can result in the buttermilk getting clumped up and dissolving, which is why it’s best not to use frozen buttermilk for drinking or cooking.

But, frozen buttermilk may still contain acidity which is what people are looking for when baking because it helps baking items that are rising.

Buttermilk is able to be stored within the refrigerator for up to 2 months while it’s safe to use it after that however, the quality will decrease quickly.

The frozen buttermilk can also be used to soften meat and leave the meat in the buttermilk for a few hours or for a couple of hours.

What is Powdered Buttermilk?

Powdered buttermilk is a great option if you don’t frequently use buttermilk, and you don’t wish to be forced to replenish spoiled buttermilk in the refrigerator every few weeks.

Buttermilk powdered has a long shelf life, and it can be stored at the temperature of the room. You only need to make what you require at one time, therefore there’s no chance of losing it. It has the same storage abilities as evaporated milk.

Powdered buttermilk is typically used for baking but is not suitable to drink. It is not likely to provide the same flavor and consistency as real buttermilk, however, powdered buttermilk has a longer shelf-life than real bottled buttermilk.

Can I Use Expired Buttermilk? Is It Safe?

Expired buttermilk is fine provided it doesn’t have an unpleasant, strong scent and is not excessively dense to drink, or in the event that there is mold.

You can make use of leftover buttermilk for recipes that require to be cooked, like pancakes, biscuits, or pie.

If the buttermilk has not reached the expiry date but appears to be fine it is possible to freeze it to be used at a later time however, it shouldn’t be frozen again after this.


Can Expired Buttermilk Make You Sick?

The expired buttermilk can make you sick because of the lactic acid, which makes buttermilk sour. If you consume expired buttermilk, which was not kept at recommended 40°F temperatures, you are running a risk of food poisoning, and expired buttermilk can make you sick.

What Happens If You Use Spoiled Buttermilk?

While it may look and smell okay, fresh food has an expiry date for a reason. If you consume food past its expiration date it is more likely that you will develop a foodborne illness. In most cases, if you are using the buttermilk before the expiry date then it will be absolutely fine to use.

Can You Use Old Buttermilk For Baking?

If you’re concerned that you won’t use your buttermilk before it expires, freezing it may be best. However, freezing buttermilk will alter the texture and flavor of your product and usually only works well in baking. Avoid purchasing unpasteurized buttermilk which can increase your risk of foodborne illness.

Does Buttermilk Expire in fridge?

According to the USDA, buttermilk can be kept in the refrigerator for about two weeks. It can also be frozen for up to three months. Keep in mind that the buttermilk could have been mishandled in shipping or at the store, left out at room temperature.

Is Buttermilk Supposed To Taste Sour?

The abundance of acid kills off virtually all of the bacteria that produce the buttery-tasting diacetyl. So three-week-old buttermilk will retain its tartness (from lactic acid) but lose much of its signature buttery taste, giving it less dimension.

What Should Buttermilk Look Like?

Buttermilk should look thick and lumpy, it doesn’t look great but it tastes great especially cakes. Substituting buttermilk is not fun.

Does Buttermilk Always Smell Sour?

The distinct tangy odor unique to buttermilk is due to bacteria causing the fermentation of the lactose found in milk. This leads to the production of lactic acid, which reduces the normal pH levels of dairy. While its acidic, tart aroma is normal, buttermilk should never smell overwhelmingly sour unless it’s gone bad.

What Can I Make With Expired Buttermilk?

  • Use it to bake. Buttermilk can make super tender cakes, quick easy breads and biscuits, and works with both sweet and savory flavors.
  • Make a batch of pancakes, then freeze them.
  • Make a creamy salad dressing.
  • Make buttermilk fried chicken and add a portion of coleslaw for dinner.

Does Buttermilk Have To Have Lumps?

Buttermilk usually has little clumps and lumps that can be removed by stirring however should it become extremely large and it is difficult to pour it out, it is not recommended to make use of it.

How Do I Make Buttermilk With Milk?

If you’re in need of buttermilk, but don’t have it to make it, you can create your own with regular milk.

You can add some white vinegar distilled or, alternatively, make lemon juice with the regular milk, and allow it for at least 10 minutes. The milk will become thicker and can be used instead of buttermilk.

How to Keep Buttermilk Fresh For a Longer Time

If you don’t wish to be concerned about whether or whether your buttermilk is been sucked away, keep it in a refrigerator and make use of it within one or two weeks. If you require a longer shelf life, place the buttermilk into the freezer.

The easiest way to know the difference if your buttermilk has gone off is to sniff it, check for any signs of spoilage, and also check whether the texture is lumpy. If there are any indications of the buttermilk not being as good then you need to throw it out.

Norah Clark

Norah Clark

Norah Clark, the founder and editor of YummyTasteFood! She's a seasoned food writer and editor with over a decade of experience in the hospitality industry as a former pastry chef, sous chef, and barista. When not writing about food, she explores new recipes or travels the world for culinary inspiration.