Does Buttermilk Go Bad？How Long Does It Last?

Buttermilk is a delicious dairy product, slightly sour, low fat, healthy, and useful for baking, but delicious to drink as well. If you like to bake, it is very likely that you have some in your fridge.

But how long has it been there? Is it still good? Does buttermilk go bad? And if it does, how long does buttermilk last? Let’s investigate and find out how to care for buttermilk so it does not kill us because we forgot when on earth we opened that container.

Does buttermilk go bad?

Unfortunately, buttermilk can go bad if you keep it unopened more than couple of weeks past its expiration date, you leave it out of the fridge or you leave the left-over buttermilk longer than couple of weeks in the fridge.

When you think about it, if you regularly use buttermilk in your baking or cooking, there is no way you will keep an open container in the fridge longer than couple of weeks. You will use it much sooner.  And keeping any milk product out of the fridge is just playing with fire.

The buttermilk you buy at the store is called cultured buttermilk and it differs greatly in quality, ingredients and how long it can last from the naturally made buttermilk that is a by-product of making butter.

How long does buttermilk last?

	Buttermilk (unopened)	Buttermilk (opened)
Refrigerator	up to 7–14 days past expiration date	up to 14 days after opening
Freezer	3 months	3 months

Source: Healthline

How long does buttermilk last depends mostly on the temperature it has been kept on. Besides, keep an eye on the ‘sell by’ date, which does not mean much, because it does not say ‘do not eat after this date’, just ‘do not sell after this date.” Open or unopen, keep your buttermilk in the refrigerator below 40°F (4.4°C) for a maximum of two weeks.

Even with all the precautions, you cannot know whether the seller or the shipper kept your buttermilk out of the fridge at some point, pretty much making sure that it will spoil much faster than the commonly accepted two weeks.

The reason we worry about the buttermilk being left out of the cold is because, like other dairy products, it’s a great growing medium for all sorts of harmful bacteria. They can be introduced to the buttermilk at any stage – during the production, shipment, handling in the store and finally by you, at home. Did you drink your buttermilk from the bottle? Did you handle the bottle opening with your hands? Bacteria take any possible chance to get in and thrive. And you will pay the price.

If you keep your buttermilk in the pantry unopened, you feel secure as long as the ‘sell by’ date on the container is still ok. The only way to know that it actually is ok is to open it, smell it, taste it, look at it and judge it safe or not. Dates are ok, but you be the judge.

8 Tips to tell if buttermilk has gone bad

1. The first thing you will notice if your buttermilk spoiled is the smell. Ok, buttermilk smells slightly sour but when it is spoiled it smells REALLY sour. If you regularly use buttermilk, you will be able to recognize easily the difference in the smell compared to the smell of fresh buttermilk.
2. When you pour buttermilk into a glass and it looks like white globs floating in the greenish clear liquid, it is bad, throw it away. The bacteria caused the buttermilk to curdle and separate, creating big uneven lumps. The longer the buttermilk stays in the container spoiled, the more it will separate into clear liquid and some floating lumps
3. You see mold in the buttermilk? There should not be any mold. It is bad. Mold might form on the surface of the buttermilk, so be careful when pouring it into a glass and check if there are any mold particles.
4. The color is off, it is not white but slightly greenish.
5. If the buttermilk looks in any way different from the way you remember it looking when fresh, something is wrong it and it is better to throw it away.
6. If the buttermilk tastes sour, it is bad. It should taste tangy and buttery smooth. Why would you want to taste the buttermilk if it smells and looks bad is a big question, but make sure you do not take a big gulp or you will get upset stomach.
7. The big tip, and the first thing you should check, is the expiration date on the buttermilk container. If it is past expiration date, it might still be edible for a few days, but if on top of that smells bad and looks bad, it means it is bad.
8. If you left an open container of buttermilk in your fridge and you have no idea how long it has been there, it is probably spoiled even if it looks and smells OK. Do not risk it.

7 Tips to store buttermilk

1. When buying buttermilk, buy the one with the latest expiration date. There is no point buying it if it has only a few days left before you would have to consume it, even if you keep it in the fridge. Definitively do not buy it if it is past it ‘sell by’ date.
2. As soon as you bring your buttermilk home, put it in the refrigerator. Do not let it hang on the kitchen counter, you will shorten its life. Even if you plan on baking soon, leave the buttermilk in the fridge until you are ready.
3. Not all parts of the fridge have constant temperature. The fridge door, because of the frequent door opening, has the temperature that fluctuates, and it is not constant. Do not keep the buttermilk in the fridge door.
4. Once you open the container of buttermilk, write on it when you opened it. Once opened, it should stay in the fridge for a week or two, but not longer. If you do not write the date when you opened it, you will forget and it might stay there forgotten for years.
5. Do not stock too much buttermilk in your pantry because even unopened, it cannot be stored out of the fridge. Buy only as much you need for your next baking project, salad making plan or because your mother-in-law is coming and she loves to drink it.
6. You can freeze your buttermilk, open or unopen, and it will last you for up to three months. Frozen buttermilk does not taste the same, so it will be still great for baking biscuits or marinating your chicken but it will not taste good enough to drink.
7. If you are a big baker and need buttermilk regularly, you might contemplate buying powdered buttermilk. It is sort of like powdered milk, you rehydrate it when needed with hot water. Like frozen buttermilk, it will not taste good enough to drink, but it will do fine for baking or making a salad dressing.

The Risk of consuming an expired buttermilk

You might end up eating bad buttermilk by error, before looking at the expiration date or not paying attention to the smell or look. You will probably develop upset stomach or real food poisoning, depending on how much and what kind of bacteria ended up in your buttermilk. If you develop diarrhea or vomiting, consult your doctor and stay hydrated.

Most people do not develop any bad symptoms unless they consume larger quantity, but it is not easy to eat bad buttermilk after the first taste in your mouth.

There is a difference in opinions on using bad buttermilk for baking. While some reports claim that it is totally harmless, others say that risking food poisoning is not worth it. If your reasoning is your wish to avoid wasting food, try freezing leftover buttermilk to avoid risking that it spoils.

Can you freeze buttermilk?

The fact that buttermilk can be frozen is great news for people who hate wasting food and watching their precious buttermilk go down the drain just because it is past its expiration date.

You know best how much buttermilk you use for each baking or making a salad dressing. It is usually half a cup or a full cup. Pour that quantity in Ziploc bags that can be sealed well and place in your freezer. Since buttermilk is liquid, the Ziploc bag will be flat and, once frozen, it will not take too much space in the freezer.

When you need half or full cup of buttermilk, just take it out of freezer and leave it on the countertop for about 15 minutes or in a pot with hot water for five minutes.

Your frozen buttermilk can last for up to three months in the freezer. Make sure to write the date of freezing on the Ziploc bag so you will know when they are past their expiration date.

Summary

Buttermilk is getting more popular in the western countries, although it has been regular food item in Asia for centuries. It has a nice, tangy taste and it works very well for baking biscuits and breads, marinating meat or making a salad dressing.

Does buttermilk go bad? Yes. Buttermilk can be stored in the fridge for up to two weeks, but if left out in the temperature higher than 40°F it will spoil in a few days. Frozen buttermilk lasts for up to three months.