Does Buttermilk Smell Sour? Answered!

Last Updated on May 30, 2022 by

Does Buttermilk Smell Sour? Buttermilk is a popular baking ingredient that imparts a slightly sour flavor to baked goods. Buttermilk is a cultured product rich in probiotics, calcium, potassium, and phosphorus. It is the run-off liquid discovered after churning butter. Buttermilk is often stored in the refrigerator for a lengthy time since it is mostly utilized in baking. Are you wondering if buttermilk smells sour?

The microorganisms that cause lactose fermentation in milk give buttermilk its characteristic sour odor. This causes lactic acid, which lowers the pH of dairy products. While buttermilk has an acidic tart scent, it should never smell too sour until it’s gone bad.

How to Tell If You Have Spoiled Milk Expired Buttermilk

There are a few symptoms to look for to determine if buttermilk is off or not, so if you’re not sure whether it’s off, search for additional signals to help you decide. Here are a few symptoms to check for to see whether the buttermilk has gone bad, using all of your senses.


Buttermilk has a somewhat tangier scent than regular milk or other dairy products, but as the product ages, the smell becomes sourer.

It may be difficult to identify a particularly sour scent throughout the preservation of buttermilk. Still, after it has gone fully bad, you will be able to smell it right away. When smelling a freshly opened buttermilk carton, keep in mind that a closed carton will have a more pungent scent since the odor hasn’t had a chance to escape.


By using your sense of sight, you can tell whether the buttermilk has gone bad or not. Its look will be the most evident symptom. When buttermilk is poured out, it develops a discoloration that is easy to see.

Mold will form on the buttermilk’s surface, and the lid is kept for an extended period and has beyond its expiration date. This occurs because greater air exposure allows the bacteria in the milk to thrive and form mold. As a result, if any mold appears on the buttermilk, discard it immediately. If you drink it, you can get diarrhea or food poisoning.

The Milk’s Consistency

The consistency of the buttermilk may also be used to determine whether it is still usable or should be discarded. You can tell by looking at how it flows, and if you’re not sure, you can touch it.

Buttermilk that has gone bad has a thick, clumpy texture. When you attempt to pour it into a jar, it forms large clots and does not flow smoothly. Instead, it will be trapped in the container. And once the milk has become lumpy, it’s a dead giveaway that it can’t be saved.

However, it’s wise to keep in mind that excellent quality buttermilk also contains microscopic lumps. However, these clots are tiny and easily broken apart with a whisker. Furthermore, they will not hinder the flow when you attempt to pour the milk.

However, if the liquid sits in the carton and becomes caught when draining, you’ll know the clumps are too large to drain, and the milk is spoiled.

Taste Of Buttermilk

Buttermilk has a sour flavor with a hint of creaminess to it. When you taste the milk, you’ll notice a rich buttery flavor from the fermented milk and a little sour scent that won’t irritate your nose.

When buttermilk is squandered, on the other hand, it tastes highly sour and unpleasant. You can know the milk has gone bad when you taste it because you can’t drink it down your throat without feeling nauseated. To prevent foodborne infections, throw away the carton as soon as you discover such an unpleasant flavor.

Expiration Date

The expiration date stamped on the container is the most obvious indicator of whether something has gone bad or not. If everything else fails and you can’t determine if the buttermilk is excellent or not, check the expiry date.


Check the buttermilk’s expiry date if you’re not sure if it smells too sour or appears too thick. If the current date has passed this date, you may be certain that the milk has soured and must be discarded.

How Long Does Buttermilk Last?

There will be a sell-by and expiration date on every buttermilk. You should be able to use buttermilk up to a week beyond the sell-by date, depending on how it was kept and transported. The product degrades more quickly after the buttermilk bottle is opened. A bottle of buttermilk should be consumed within a week or two after being opened.

This depends on how well the buttermilk is stored and whether or not it has been contaminated with other products. Buttermilk must be stored in the refrigerator, whether opened or unopened. Powdered buttermilk is a good option if you want buttermilk that lasts longer and doesn’t have to be refrigerated. 

How Can You Make Buttermilk Last Longer?

Buttermilk should be kept cold and not allowed to warm up. If you aren’t going to use the buttermilk right away, keep it unopened. An opened carton of buttermilk won’t survive as long as an unopened one.

When pouring buttermilk, please keep your fingers away from the cover and never drink directly from the carton since this might introduce germs into the buttermilk, causing it to degrade quicker.

I’d also recommend storing your buttermilk in an airtight container to extend its shelf life. Buttermilk may also be frozen to extend its shelf life even more. It’s recommended not to use frozen buttermilk for drinking or uncooked dishes since freezing changes the consistency and may cause the buttermilk to clump and separate.

On the other hand, Frozen buttermilk will retain its acidity, which most people want when using it in baking since it aids in the rise of baked goods. While buttermilk may be stored in the freezer for two months, the quality will quickly degrade. Frozen buttermilk may be used to tenderize meat by marinating it overnight or for a few hours in the buttermilk.

How Is Buttermilk Produced?

True buttermilk is prepared from the liquid leftover after churning butter rather than milk. It ferments spontaneously, converting into a thick, bitter cream. The final product has a distinct strong scent and flavor.

What is offered in most supermarkets now, on the other hand, is a different species. That container of low-fat milk in your fridge began off as simple low-fat milk. After that, cultured bacteria are added, and the mixture is thoroughly cooked. Those beautiful bacteria eventually start a fermentation process by eating all of the lactose in the milk. Lactic acid now appears, lowering pH levels, increasing acidity, and giving off that distinct odor. As a thickening agent, starch is often used.

Can You Freeze Buttermilk?

Freezing leftover buttermilk is a terrific method to save money and prevent food waste. If properly frozen, it may survive up to three months. Using ice cube trays or muffin pans that you already own is a terrific option. We’ll show you how!


Because most recipes only call for a cup or less of buttermilk, not having to thaw out half a jug every time is handy. Measure how much liquid each compartment will hold in your muffin or ice container. Please make a note of the number somewhere you won’t forget it.

Fill And Freeze

Please fill all the trays with the ingredients and place them in the freezer. Place all of your new cubes in freezer bags for safe storage after they are completely frozen. Before closing the baggie, remove as much air as possible. Remember to identify them with the contents, the date, and the measurement you took earlier.


Grab the amount of cubes you’ll need when you’re ready to bake another batch of those delicious buttermilk biscuits. Allow them to defrost overnight in the refrigerator. They may be frozen if you’re making a hot meal or soup. You may even microwave them for people who required supper two hours ago. Until thawed, nuke for 10 seconds at a time.

Is Buttermilk Good For Your Health?

Buttermilk is high in probiotics, vitamins, and minerals, which are essential for good health. Vitamins A and D, potassium, calcium, riboflavin, and even phosphorus are all found. Probiotics keep the good bacteria in your stomach happy, allowing you to digest food more efficiently. Vitamin A is great for your eyes, while vitamin D is essential for your bones and teeth.

Furthermore, the additional protein it provides helps your body maintain healthy skin, bones, and muscles. When eaten in little quantities regularly, buttermilk has also been shown to help decrease cholesterol levels. This is an excellent attribute for a dish since elevated cholesterol is connected to strokes and heart disease.

While buttermilk is still a dairy product, some lactose-intolerant persons find it a suitable substitute for regular milk. This is because the bacteria eat away at the lactose, reducing its concentration. It’s useful to have alternatives, even if they may or may not work.

Conclusion on Does Buttermilk Smell Sour?

The pungent scent of buttermilk is due to the lactose-devouring bacteria it carries, as we’ve discovered. It should never smell rotten, even if it is somewhat sour. Don’t leave your carton out of the fridge, and any leftovers should be frozen for later use. Try the powdered form of buttermilk if you need something that will last a long time.