Do Walnuts Go Bad? See What You Didn’t Know About Your Favorite Nuts

Nuts are known for their long shelf life. However, they still go bad. Walnuts are one of those nuts that last several months retaining their quality. But when you don’t keep your walnuts well, they go bad and taste unpleasant.

If you have tasted a bad walnut, you’ll agree that it can mess up your palate. Although walnut will naturally last long, you should know how long, how to identify bad walnuts, and how to preserve them from spoilage.

What Are Walnuts?

Walnuts are edible seeds that grow from the walnut tree. These trees grow in many countries of the world and this is why they’re very versatile. Walnut is rich in fiber, protein, and fatty acids which provide great nutritional value.

Eating walnut provides your body with antioxidants that increase resilience against oxidative damage. Walnut also has the potential to reduce one’s risk of getting diseases like cancer, heart problems, and diabetes. Additionally, the high fiber content in walnuts can help control weight gain.

Furthermore, walnut is most often eaten raw or cooked as a snack on the go. But it is also good in dishes. You can add walnut to salad, pasta, sandwich, yogurt, and as a coating for fish or chicken.

Do Walnuts Go Bad?

Yes, walnut goes bad. The nuts have a long shelf life but different factors influence how long your walnuts last and retain their quality. How you store the walnuts (that is, shelled or unshelled) and where you store them determines how long they’d last.

Additionally, despite their long shelf life, walnuts go bad because their nutritional composition includes oils and fatty acids that make the nuts oxidize quickly and go rancid. Therefore, you need to know all these and store the nuts properly to prevent this.

Do Walnuts Go Bad in the Shell?

Unshelled walnuts do not go bad, at least not quickly. The shell is a protective covering that shields the kernel from external factors that can make walnut go off.

Unshelled walnut lasts for twelve months if you keep them properly at room temperature. Sometimes, with different weather conditions, walnut may last longer than twelve months.

Moreover, in a refrigerator or freezer, you can expect the nuts to last longer. However, the longer you store unshelled walnut, the more the number of rancid nuts you’ll get when you’re ready to use them.

SEE: Here’s How to Tell if Your Almond Butter Is Still Good

Do Shelled Walnuts Go Bad?

Shelled walnuts are more exposed to spoilage because the shell that covers the nuts is no longer there. Walnuts without their shells will not keep for long. At room temperature, you can keep nuts for up to three weeks but in an airtight container.

In addition, if you choose to store them in a refrigerator or freezer, you can enjoy walnut of good quality for 6 months up to a year.

Do Walnuts Go Bad in the Fridge?

Walnut keeps longer when you store them in the fridge. Shelled walnut can last up to six months in the fridge if you store them in an airtight container or freezer bag.

Proper packaging before refrigerating will help to keep out moisture and keep the nuts fresh.

Do Walnuts Go Bad if Frozen?

Freezing is the way to preserve walnut long-term. With proper packaging and sealing, the walnut should taste fine even after thawing.

Do not freeze ground or chopped walnut. Freeze the nuts whole and process them when you’re ready to make use of them.

SEE: How to Stop Food Spoilage and Food Poisoning

Do Chopped Walnuts Go Bad?

Chopped walnuts have a very short lifespan. Keeping the nuts in the open exposes them to quick spoilage. Freshly chopped walnut will last a few hours to one day on the kitchen counter. But, if you refrigerate the chopped walnut, you can preserve them for about a month.

While the chopped nuts are in the fridge, you should keep them in an airtight container, away from other foods that can trigger spoilage.

Do Roasted Walnuts Go Bad?

Roasted nuts go bad after exposure to air and moisture. Moreover, because they are nuts anyway, they’ll go rancid after a few hours. Roasted walnut will last only a few hours if you leave them in the open.

In an airtight container, you can keep your roasted walnut for up to two weeks. The nuts will keep better and longer if you refrigerate them.

SEE: Do Almonds Go Bad Or Not? Find Out Here

Do Candied Walnuts Go Bad?

Candied nuts will go bad after some days, depending on how you preserve them. The nuts will keep well for 1-2 weeks at room temperature. Candied walnut can last up to a month if you keep them away from air and sunlight.

What Is the Shelf Life of Walnut?

The shelf life of walnut varies with how they are stored.

  • Whole (unshelled) walnut has a shelf life of 12 months anywhere they are stored
  • Shelled walnut will last up to 3 weeks in an airtight container in the pantry, 6 months in a refrigerator, and 12 months in a freezer
  • Processed (chopped or ground) walnut will keep for 1 day at room temperature. If you refrigerate them, you can have your nuts around for up to one month. If you want to store the nuts for longer, freeze them so you enjoy processed walnut for up to 6 months

Can You Eat Bad Walnut?

Eating expired nuts may not threaten your health but it’s not good either. You risk gastrointestinal problems if you eat bad walnut. Also, the awful taste of bad walnut can spoil your palate for a few hours.

SEE: Food Poisoning Signs You Need to Know

How to Tell if Walnut Is Bad

Examine the shell

If the shell of the walnut looks dried out and shrunken, the nut in it is most likely rancid. If you want to have a look at the inside, break it open and examine the nut as well.

A dried-out nut, a nut with net formation, or the presence of organic growth are signs that the nuts are not fit for food anymore.

SEE: Get the Answers You’ve Been Looking for on How Long Tofu Lasts

Touch the nut

Good walnut feel firm in the hands, this is something bad nuts do not have. A bad walnut will feel slimy or slippery. If you notice this, you should toss the nuts away.

Mold growth

You may not observe mold growth on the shell of a walnut. This is another reason why you should break your walnut and look at the inside before you eat it. Mold growth on walnut appears as dark spots on the nuts. Throw away nuts that show this sign.

An off smell

A good walnut has a slight aroma but when they’re going bad, they smell rancid. A rancid walnut smells more like oil. And this is a result of the oxidation of natural oils and fatty acids present in the nuts.

Taste the nuts

If after checking the outside for signs of spoilage but you’re not so sure about the quality of the walnut, bite a little and taste it. Bad walnut is bitter and tastes very awful.

SEE: How to Get Free Food Coupon at Krispy Kreme

How to Preserve Walnut

  • For long-term storage, keep walnuts unshelled until you’re ready to use them
  • Store shelled, chopped, and ground walnut in the fridge or freezer
  • Also, keep unshelled walnut in an airtight container and far away from foods with strong smells like onion
  • In addition, walnut should be kept in a cool, dry place like the pantry
  • For long-term storage, freeze the walnuts

SEE: Easy-Peasy Methods to Salt Cashews


Why do walnuts go bad so quickly?

Walnuts go bad quickly because of their high content of polyunsaturated fatty acids and oils that make them oxidize quickly and go rancid.

Can you get poisoned from raw walnut?

Common side effects of eating raw walnuts, especially black walnuts, are signs of food poisoning. Raw walnuts contain harmful bacteria that can lead to salmonella poisoning but it’s not likely to result in a serious illness.

Why do you feel nauseated after eating walnuts?

If you have nut allergies, you’re likely to have stomach cramps with vomiting a few hours after eating walnuts.

Should you wash walnuts before eating them?

You should wash walnuts before eating them because they naturally contain harmful bacteria that can cause food poisoning. However, packaged walnuts may not need to be washed.


Walnuts are a rich source of folic acid, omega-3 fatty acids, and antioxidants. They are very nutritious and can help improve the appearance of your skin. Walnuts have a long shelf life but it’s dependent on how well you store them.

Generally, unshelled walnuts last longer than shelled walnuts. Store your walnuts in an airtight container and they will keep well at room temperature. But for long-term storage, keep the walnuts in a refrigerator or freezer.

Thanks for reading.

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