Does Yogurt Go Bad?

There was this big sale, and you stocked up on yogurt. It’s been two weeks since, and now you realized that you were a little too ambitious. In other words, you’ve bought too many and now you have a few yogurts nearing the date on the label. Does yogurt go bad?

Or maybe you use yogurt mainly for cooking. A typical recipe uses only half or even a third of the container, so you’re often left with a half-open yogurt. You’re not quite sure how long you can store the rest, or if freezing the leftovers is any good.

If some of these questions sound familiar, this article is for you. In it, we go through storage, shelf life, and going bad of all kinds of yogurts.

Yogurt, fruits, and nuts in a glass bowl
(credit: Niclas Illg)

How To Store Yogurt

Like similar products such as kefir or sour cream, you should store yogurt in the fridge. That’s true for pretty much all kinds of yogurt, including plain natural, Greek-style, and flavored ones.

Once you open the package, make sure you cover it tightly. Without a cover, it starts to dry out, and it might pick up any strong odors from the fridge.

If you will use the leftovers within a day, using the aluminum top of the package is usually enough. But if you expect the rest to sit in the fridge for a few days, pour the yogurt in a mason jar or a small airtight container. This way it will retain freshness for longer.

Time and time again I’ve seen questions like “how long can yogurt be out of the fridge without going bad?“. There isn’t a right answer to such an question, because it’s impossible to tell.

Sometimes it can be an hour, sometimes a few hours. Plus it depends on the temperature it sits in, and so on. All in all, you should try to limit the time yogurt is outside of the fridge to the minimum. That means it shouldn’t sit for hours in the trunk with other food items if it’s hot outside.

Tip

In the summer, try picking up all the refrigerated items right before you go to checkout, to minimize how long they stay at room temperature.

Glass of yogurt, nuts, and blueberries
(credit: Ellieelien)

Can You Freeze Yogurt?

There’s this issue of whether or not you can freeze yogurt. In short, you can freeze yogurt, but just like buttermilk or other dairy products, it will separate once thawed. Stirring it will help a bit with getting some of its texture back, but don’t expect miracles here.

Because of that, frozen and thawed yogurt is recommended for cooking and baking only. In such dishes, the changed texture doesn’t matter all that much. Also, bear in mind that thicker yogurts generally freeze better, so you might have more success with freezing Greek-style yogurt than with the plain one.

Fruit salad with strawberries, almonds, milk and yogurt
(credit: Dani Rendina)

How Long Does Yogurt Last

Pointing out the exact shelf life of yogurt is difficult. There are a few things that come into play here.

First, it’s the type of yogurt (plain, Greek, Icelandic, flavored, reduced-fat) that matters. Second, it’s the ingredients and whether or not it contains preservatives. The third factor, and one that you have limited information about, is how it was stored before it got to the shelves. If your yogurt was mishandled before it got to the store, it could spoil early.

Generally, the first thing to do is to check the date on the label. Usually, it’s a sell-by date. That date informs you how long the store can keep the product on the shelves. That also means that the dairy product should easily retain freshness for a couple of days longer. In case of yogurt, it’s usually up to a week past that date. Of course, it can as easily be spoiled a day past the date on the label, especially if it’s free of preservatives.

Once you open the package, you should use it within a week. That is, of course, if you store it properly. While a week sounds nice, to get the best quality I recommend using the yogurt within 3 to 5 days tops. That’s, of course, a general estimate and will vary for different styles and brands.

 Fridge
Yogurt (unopened)Sell-by + 1 week
Yogurt (opened)5 – 7 days

Please note that the periods above are rough estimates and dairy products can easily spoil way earlier.

Homemade Yogurt
Image used under Creative Commons from Mom the Barbarian

How To Tell If Yogurt Is Bad

This process is fairly simple. The first thing you should do is to look for any signs of mold, other organic growth, texture change, or any kind of discolorations. If you find either one, discard the product.

If there’s some liquid on top of the yogurt, fear not. It’s whey that has separated, and you can stir it in. The process is natural and not harmful in any way. Also, it happens pretty much only in preservative-free yogurts.

The next thing to do to determine whether the yogurt is bad is to check its smell. If it has a stale, sour, or any other off odor, throw it away. If the yogurt looks and smells okay, you can taste it. A sour taste is a sign the yogurt is past its prime, and you probably want to toss it out.

Last but not least, if your half-open yogurt sits in the fridge for more than a week, or an unopened one is a couple of weeks past the date on the label, just discard it. Same thing if you left it at room temperature overnight by accident. In either case, it’s better to cut your losses and don’t risk foodborne illness.