How to Tell if Greek Yogurt is Bad

Simon King
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Does Greek Yogurt Go Bad?

Yes, Greek Yogurt goes bad but it is not very optimal. It can be used, but it is not the freshest product. Yogurt is a dairy product and it contains both lactic acid-producing bacteria and lactic acid. These bacteria ensure that natural fermentation occurs and yogurt stays good for a fairly long time.

When the bacterial activity is stopped by heat or vacuum, lactic acid stops forming, causing your yogurt to sour quicker.

If stored cold and consumed within a reasonable amount of time, Greek Yogurt is actually an excellent source of protein. It contains 18-25% of the daily value of protein per 100-gram serving. You should use your common sense when it comes to consumption though. If you have doubts about whether your Greek Yogurt is still good, throw it out just to play it safe.

Expiration Date

The time period from which "good until the best before date" is based on the seller's opinion. That usually means that the item can be consumed until it begins to taste and smell bad. Manufacturers usually recommend that you consume products during the length of time indicated but that’s not a guarantee. In eggs and dairy, for example, the products usually have an even shorter shelf life.

In many countries, including US and Canada, there is no established "use by date" and every manufacturer may include its own.

Dairy products should be consumed before their best before date, not after, but many people usually end up keeping them beyond the expiration date.

In this case, all you can do is personal taste testing.

Test for bad items by opening the lid and taking a whiff. If the milk smells different it may be spoiled.

Greek yogurt will have a thicker consistency when you make it yourself. It is best if it is used as soon as possible but should remain good for a longer period of time in comparison to regular yogurt.

A short shelf life is one of the possible explanations of how a lot of people find their yogurt viable for a prolonged period of time.

Sniff and Tell

In general, yogurt will last in the fridge for about a week. Some of the best indicators are the smell and the texture. A sour or rancid smell is a sign of spoiling yogurt. It could just be a case of "bad" because of how some people like their yogurt or because of bacterial activity.

The texture of the yogurt is an important indicator, especially if you are not consuming it within the first couple of days. If it is soft and runny, it needs to be thrown in the trash. Yogurt that is runny means it is most likely about to expire.

Of course, at home, people have varying tastes and preferences. Some people like sweet, creamy yogurt. Some people like the tangy taste of tart yogurt. As long as you are not in doubt about whether yogurt is bad or not, you can consume it. Just avoid touching the outside.

If the liquid is runny, keep these steps in mind:

Keep the top of the yogurt sealed, avoiding any further contamination.

Put the yogurt container in a container. Line containers with paper towels.

Freeze the container and yogurt in a deep freezer for 2-3 days. Keep any extra weight on top of the freezer.

Remove from freezer and thaw in the fridge.

Do You See Mold?

Greek yogurt causes quite the debate among foodies and home cooks. Many say it’s better than regular yogurt because it’s less processed. It can also be used as a replacement or an additive in some traditional recipes, such as this meat pie recipe. Greek yogurt is slightly thicker than most yogurts that you can buy, and some foodies prefer it because of this.

But sometimes you may lose the contents of your refrigerator, or accidentally leave the yogurt out of the refrigerator for too long. If you plan to use yogurt in the next couple of days and need to tell if yogurt is bad quickly, here are some things to look for.

There is an area below the “use-by” date on the yogurt container that will display a number. This is transpiration dates, and it’s the amount of time after the product hits maximum yogurt goodness when the product will begin to decline in taste and flavor.

Most acceptable yogurt containers will use the line method, where a line will run down the container from the production date to indicate this.

Regardless, if your yogurt has been sitting in the refrigerator for a while, even if it’s not expired, it is best to toss it.

Store-bought yogurt is typically only good for a week versus three to five days for homemade yogurt.

Do You See Water?

The appearance of water in yogurt is generally one sure sign that yogurt has gone bad. Other signs include an unusual, musty odor and the presence of mold. Although yogurt starter culture bacteria, such as Lactobacillus bulgaricus and Streptococcus thermophilus control the souring process, they do not prevent water from accumulating in low-acid dairy. Look out for water separation and thin, grayish-white curds that are floating atop the water to determine when to discard yogurt.

Another sign that yogurt has spoiled is the development of mold. If you see mold on yogurt, discard it immediately. For a yogurt that has water separation, scrape off the top portion to check the condition of the yogurt part underneath. You can scrape off a little at a time until you’re confident that the bottom part of the yogurt is still fine. If you dump out the whole container, you’ll never know if there was more damage underneath, even though it may look fine.

Taste It

As a general rule, when checking the expiration date of any food, you'll want to rely on your senses of smell, sight, and touch to detect bad yogurt. If the yogurt has an off odor or is moldy or fuzzy, toss it without tasting it. Yogurt that is overripe or expired is a breeding ground for bacteria that can make you ill.

If the yogurt is obviously expired, then toss it. If you're not sure, then give it a sniff and a taste. Bears, raccoons, and other scavengers are attracted to open containers of food. Always smell the yogurts before opening, if you have any reason to suspect that it has been tampered with or consider tossing it.

What Happens If I Eat Bad Greek Yogurt?

There is nothing wrong with eating Greek yogurt as long as you are careful about certain aspects.

You should give preference to the brands that have “Live and Active Cultures” printed on the container and don’t buy the flavored ones. Why? Flavored Greek yogurt has already undergone some fermentation during which bacteria other than the good bacteria were used for producing that flavor.

If you are feeding the yogurt to a baby or a toddler, you need to look for a brand that specifically states “Contains Live and Active Cultures” on the label. The good bacteria are necessary if you are giving them to your kids.

If you are buying frozen yogurt, look for something that has been produced at least the same day. This will ensure that it has the fresh taste.

The taste of frozen yogurt can be preserved in the freezer for about three months.

Any yogurt that shows signs of mold should immediately be discarded because it could be harmful.

The other reason for discarding yogurt is that it turns rancid quickly. If you wish to use it other than eating it right away, store it in the freezer.

Stomach Cramps

If you have recently eaten Greek yogurt and have developed stomach cramps or other symptoms, you might be worrying about food poisoning. Most people associate food poisoning with bacterial infections, but, in fact, the most common type of food poisoning is caused by a virus.

When food is contaminated by certain viruses, it can’t make you sick until you’ve eaten it. Once you’ve eaten it, the virus can cause food poisoning symptoms in a matter of hours. The good news, unfortunately, is that most of the viruses that cause food poisoning are relatively harmless. The main symptom is stomach cramps, which should go away within a few hours.

The best bet for recovery is to rest, drink plenty of fluids, and to eat something bland, like plain cooked rice or bread. The bad news is that some viruses can also make you more likely to get other, more serious viruses in the near future, so you should be vigilant about remembering to wash your hands after using the bathroom or changing diapers.


The texture and smell of vomit are very familiar. So if you suspect that your dog has been vomiting, it is easy to feel confident that you are right.

Even though we know that vomit has a certain look and smell, it isn’t good enough to rely solely on your eyes or nose to tell if your dog is vomiting.

There are many things that can cause vomiting. So it’s necessary to interpret your observations and reach a diagnosis. This can be done using a technique called the Q-C Test.

The Q-C Test is named by its inventor ‘Kyle’ from Veterinarian Stewart Brothers, a holistic veterinary practice.

The Q-C Test consists of three questions. Answer yes or no to each, and if two or more are yes, you are almost certain that your dog has a stomach issue.

{1}. When the dog vomits, is there any yellow or green discharge?
{2}. When the dog vomits, is there any blood?
{3}. When the dog vomits, does it have a crazy, erratic behavior as if the dog is crazy drunk? (The crazy drunk part means that it keeps trying to vomit and can’t seem to get it out of its system.)


That is not food poisoning. Remember when we said we can get probiotic food poisoning? Well, this is it. Your body can actually process all that good bacteria as if it was a bad bacteria. Depending on your body, after eating probiotics, you can get diarrhea or constipation. It’s a tricky one.

It’s usually temporary. Once your body gets adjusted to the probiotic foods, you will usually be OK. In the meantime though, you can avoid it by picking a yogurt with a shorter shelf life. Since the good bacteria only survives for a few days.

I Don’t Want to Throw out My Greek Yogurt Yet

Wherever your yogurt culture comes from, you can assume that it will not be packaged in sterile conditions. It may have bacteria already in it or growing on it when you open the container. According to the National Center for Biotechnology Information–

[t]he lactic acid producing bacteria are similar for both types of yogurt. However, the flavor components of Greek yogurt are different than the flavor of regular yogurt.

When you are feeling uncertain about the validity of your Greek yogurt, the following facts may help your decision:

{1}. When it is bad.
{2}. When it isn’t bad at all.
{3}. When the order of degradation is conducive to eating or tossing.

The Bad Thing about Bad Yogurt

First of all, let’s get the out the way.

Bad yogurt means that it is contaminated with something that will make you sick, not just that it won’t taste good.

The smell will be a dead giveaway. Bacteria produce these compounds, which are volatile, meaning that they immediately start to invade your nasal tract. Shudder.