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How to Tell if Yogurt Is Bad

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Yogurt is a great food that sits in most Americans’ refrigerators. It’s versatile as an ingredient in recipes and is typically a good source of protein.

People eat yogurt for breakfast, add it to dressings, and even bake with it.

One of the challenges with yogurt is its relatively short shelf life. Yogurt spoils much faster than most other foods.

So how do you know if your yogurt is bad?

Typically, it’s easy to tell when yogurt spoils. You can tell it’s no longer good when it smells or tastes sour or sharp.

Plastic cups of yogurt and spoons on white wooden table

Yogurt has a smooth, light flavor, so a strong taste is a sign you should throw it away. Likewise, when the yogurt sits for too long, it can mold, or the water separates from the curd.

No one wants to eat bad yogurt.

Thankfully, rotten yogurt has such a strong smell and flavor you won’t want to eat it. But, on the other hand, it can be hard to notice rotten yogurt if you’re using it as an ingredient.

Here are ways to tell if yogurt is bad.

How to Tell If Yogurt Is Bad

As mentioned, it’s pretty easy to know when your yogurt is bad. Usually, you won’t want to eat it once you smell it.

But here are some ways to tell if you should throw it away.

The Smell

Young girl covering her nose with hand from smelly spoiled yogurt

The smell is your first sign if yogurt is rotten.

Yogurt should have a light, mild scent. It should smell relatively mild even if it’s flavored yogurt, like peach or vanilla.

Anytime your yogurt smells sharp, sour, or strong, it’s probably bad.

Rotten yogurt smells rancid – you won’t want to keep smelling it. If that’s the case, throw it in the trash.

How It Looks

Spoon of homemade yogurt in wooden bowl on the table

If your yogurt passes the smell test, you should look at it to tell whether it’s still fresh.

Fresh yogurt will look creamy and solid.

Some yogurt is thicker than others but look to see if water is separating from the yogurt; it’s an early sign the yogurt is going bad.

Because yogurt is such a delicate food, it will start to separate relatively quickly after you buy it.

For example, leaving it in the fridge for several days will often result in water separation. However, it’s usually still good unless the yogurt starts curdling and smells foul.

Mold Growth

Cup of yogurt with mold mildew on wooden table

Mold is a sure sign that yogurt is bad.

Mold growth happens more often in larger, open yogurt containers because there is more air and, thus, more mold spores.

Mold on yogurt can be green, blue, or black.

You should never eat any yogurt with mold on it.

The Taste Test

Young woman eating yogurt in the kitchen at home

If your yogurt smells good, has no mold, and looks OK, then you should give it a taste!

Good yogurt will taste pleasant and fresh.

How yogurt tastes depends explicitly on its flavor, but generally, it should be light and have a clean flavor.

A strong or lingering aftertaste could signify spoiled yogurt, so proceed with caution.

Storebought yogurt will sometimes last longer than homemade yogurt because food makers have a refined production process designed to extend their products’ lifespans. In addition, sometimes, they add preservatives to the yogurt to help it last longer.

Camera inside fridge, man taking out yogurt

Can Yogurt Go Bad in the Fridge?

Yogurt can go bad in the fridge, just like any other food. However, with yogurt and many other dairy products, like sour cream, you have less time before they start to turn.

In general, unopened yogurt can last weeks in the fridge. The lifespan shortens once you open a container.

Then, you usually only have a few days before the water separates and you start to see mold growth.

Every yogurt container you buy should have an expiration date stamped on the cup or container.

Eating or using the yogurt before the expiration date is always best.

What Does Spoiled Yogurt Taste Like?

Spoiled yogurt will have a bad taste, sort of like drinking sour milk. It can have a more intense aftertaste too.

Bad yogurt will often taste slightly carbonated.

In addition, you’ll feel some minor bubbling sensation when you eat a spoonful.

It’s easy to know when yogurt is bad because you won’t want to keep eating it. If it tastes good, though, it should be fine.

Yogurt in glass pots with expiration date

Can You Eat Yogurt After the Expiration Date?

You can eat expired yogurt, but it’s not always a great idea.

The expiration date is there for a reason, but grocers and food manufacturers must operate with a more considerable margin of safety than most people think.

You probably won’t have any issues if you eat yogurt a day after it’s expired.

However, you should always give it a smell and a small taste test.

Make sure you’re not cooking with rotten yogurt or putting it into something else, like a fruit parfait, which will ruin the other ingredients.

woman having stomach ache sitting on the sofa at home

What Happens If You Eat Bad Yogurt?

Eating rotten dairy products can make you sick, whether it’s cheese, yogurt, milk, sour cream, or anything else.

People who eat bad yogurt will usually be fine. However, some people have gone to the emergency room because they ate bad dairy products.

Hopefully, these tips will keep you from eating bad yogurt. As always, smell it, inspect it, and decide whether you want to eat it.


Yogurt is a fantastic food that’s usually very healthy. Of course, you’ll want to avoid overeating sugar, but things like Greek yogurt are a terrific source of protein and much better for you than many other snacks.

Keep your yogurt covered, sealed, and in the fridge to make it last longer and prevent mold growth or curdling. Even then, you can only expect the yogurt to last a week or two before it starts to go bad.