Does Nutritional Yeast Go Bad?

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Like other dry goods, there are a lot of questions surrounding how long nutritional yeast can keep. In this article, we’ll answer the question, ‘does nutritional yeast go bad?’ as well as other common nooch shelf life inquiries.

Nutritional yeast is a pantry staple for many vegans. Like other dry goods that tend to sit on the back shelf, it can be forgotten about from time to time. If you’ve just uncovered a lost jar of nooch, you may be wondering if this plant-based favorite can spoil.

So, does nutritional yeast go bad? The short answer is yes, nutritional yeast does expire and it certainly can go bad. But the timeline around this depends on many factors.

Keep reading to find out how long nutritional yeast keeps, how to tell when it’s gone bad, and to learn a few tricks to extend nooch’s shelf life.

How Long Does Nutritional Yeast Keep?

In general, a new batch of nutritional yeast will keep for about two years with minimal risk of going bad. Nooch that was purchased in an air-tight container or jar is likely to last a little longer than bulk nutritional yeast flakes and powder that have been transferred from one container to another.

This is because bulk yeast is more likely to have been exposed to oxygen more often. And oxygen is one of four things that hastens the degradation process of nutritional yeast and other dry product foods. In addition to oxygen, exposure to moisture, heat, and light will also increase how quickly your nooch goes bad.

How Long Is Yeast Good After The Expiration Date?

Like the expiration dates printed on many dry goods, the expiration date on bottles of nooch is really just an estimate of the minimal amount of time the product will last.

If the nutritional yeast was kept away from light, heat, moisture, and oxygen, odds are, it will last a lot longer than the date printed on the packaging. How long, exactly, again will depend on the source of the nooch and how you have stored it. 

Instead of going off an exact timeline, your best bet is to use your senses to determine if the nooch is still good before you use it. More on how to tell if nutritional yeast has gone bad in a minute.

Can Unopened Nutritional Yeast Go Bad?

Packaged nutritional yeast is sealed against invading oxygen and moisture. This type of product is much less likely to spoil quickly than nooch from the bulk bin.

Even if the package is never opened, prepackaged nooch can eventually go bad.

Most of the degradation it will experience will come from exposure to light and heat, which will cause nutrient damage but shouldn’t make the product dangerous to consume. 

But even a sealed package can let minute amounts of oxygen in overtime. With this oxygen comes tiny amounts of moisture that can speed up the spoiling process.

Once again, two years is a good place to start as a cut-off for how long you should keep unopened nutritional yeast before throwing it out.

How Long Is Nutritional Yeast Good After Opening?

Once you open a prepackaged container of nooch, you immediately introduce oxygen and moisture into the environment. How much oxygen and moisture is introduced over the course of using the nooch will determine how long nutritional yeast flakes and powder will last after opening.

If stored in a dry, dark location in an air-tight container, most nooch will stay good for two years after being packaged. Assuming your storage methods are adequate, this remains true even if the container has been opened.

Can I Use Expired Nutritional Yeast?

Dry goods don’t immediately go from perfectly fine to rotten overnight. So, it makes sense that you have a little leeway when it comes to expiration dates. 

What the expiration date of your favorite cheese substitute is really telling you is when your product is likely to stop tasting as fresh as it should. 

If you notice changes in taste, smell, and, most importantly, consistency, it is time to toss out your nooch and replenish your supply with a fresh batch. This is true whether the expiration date has come to pass or not.

Is Nutritional Yeast Supposed To Be Refrigerated?

Nooch does not need to be refrigerated. It is a shelf-stable product that should be stored in a dark, dry place. That said, storing your nooch in the fridge can help prolong its life.

The fridge offers two things that are beneficial for extending the shelf life of nooch. One, fridges are pitch-black most of the time, which means limited exposure to degrading light. And two, refrigerators are nice and cool.

The nutrients and enzymes in nooch are more likely to stay good for longer in a cool environment. 

How to Tell If Nutritional Yeast Has Gone Bad

There are two ways nooch can go “bad.”

The first way is by getting stale. Stale nooch won’t hurt you, but it doesn’t taste as good as it should. Nooch generally goes stale when it is very old or when it has been exposed to free-flowing oxygen for an extended period.

Stale nooch has a lighter color than the deep golden color or yellow color of fresh nutritional yeast. It will also lose its nutty, cheesy aroma and give off little to no odor. The cheesy flavor and nutty flavor will also be greatly reduced and that typical stale taste will take over.

Nooch will also go bad if exposed to moisture. This can quickly lead to mold growth that can cause the product to spoil. 

If you notice your nooch has suddenly gotten darker or browner in color, has a malty or sour smell, or if it has become clumpy, throw it out. Nooch that has a noticeably bitter taste or malty flavor should also be thrown out. These are all signs your nooch has gone bad.

Can You Get Sick From Expired Nutritional Yeast?

Stale or expired nutritional yeast on its own will not make you sick. The nutrient content is much lower in older nutritional yeast, but it won’t harm you. As we discussed before, these shelf life dates are only estimates of when your product might start to turn.

When old nooch becomes dangerous to eat is when it’s been exposed to moisture and mold. Just as moldy bread and flour can make you sick, so can moldy nutritional yeast.

Nooch that is clumpy or has spots of green, brown, or blue, is definitely not safe to eat and should be thrown out.

If you find yourself suddenly out of nooch and in need of a substitute, check out these nutritional yeast substitutes that work surprisingly well.

Does Nutritional Yeast Contain Mold?

Fresh nooch should not contain any mold. 

The product consists of active yeast cells raised on a medium of beet molasses or sugarcane. Much of the nutritional content comes from nutrients added to that medium or mixed with the yeast after it has been harvested. Once it is done growing, the active yeast, or yeast microbes, are heated and turned into inactive yeast product.

Unless something has gone terribly wrong during this process, the final product should contain only deactivated yeast. 

If the product is exposed to moisture at any point after the drying process, mold can be introduced and grow on the yeast product. This is most likely to happen in humid environments and if dry spoons are not used to remove nooch from the container. Any water contact will introduce moisture and possibly mold to the product.

Can Nutritional Yeast Cause Thrush?

No, eating nutritional yeast cannot cause thrush.

Thrush is a condition in which the candida yeast naturally present in your body begins to grow out of control and form thick layers of yeast in the mouth. Like other pathogenic yeast infections, thrush is caused by an imbalance rather than exposure to alive yeast products.

Nooch is made from Saccharomyces cerevisiae. This species does not belong to the Candida genus and is not related to the yeast that causes thrush. Furthermore, nooch is not an active yeast product.

Nooch is deactivated during production (similar to brewer’s yeast) which means it is not alive and cannot reproduce inside your body.

Can Nutritional Yeast Cause Stomach Problems?

Generally speaking, no, nooch is not likely to cause stomach problems. But there are a few exceptions to this rule.

If you’re allergic to any of the ingredients in nooch, namely the yeast part, then consuming it could cause stomach problems and even anaphylactic shock. 

Nooch also contains a high amount of fiber. If you’re not used to consuming a lot of fiber in your diet, then a sudden increase in nutritional yeast consumption could cause some digestive upset. But given the standard serving size of nooch (about one to two tablespoons), this is pretty unlikely.

Of course, nooch that has gone bad and contains mold could definitely upset your stomach if you ate it. This is why it’s important to check your nooch for signs of spoilage before you dig in.

If you’re worried about finding a quality nooch product, check out our list of the best nutritional yeast brands.

Store Nutritional Yeast for Lasting Enjoyment

Now you know that nutritional yeast does, in fact, go bad. But when and how this happens depends largely on how you store your nooch and when you open it.

Nooch exposed to light, moisture, and oxygen will go bad faster than nooch stored in a cool, dark, dry place. Exposure to temperature shifts and heat can also take a toll on your nooch by destroying the nutrients and enzymes inside it.

Nooch that has been sitting for over two years or has gone past its expiration date is more likely to go bad. But this isn’t a guarantee. Likewise, fresher nooch can be spoiled if moisture was introduced and mold has grown.

Sara Seitz

About the Author

Sara Seitz is a freelance writer living with type 1 diabetes. Her search for better health and better control of her blood sugars led her to a plant-based diet. When she isn’t experimenting with new vegan recipes, she’s helping spread the word about how plant-based is better for people and the planet. More articles by Sara.