When most people think of nuts, they think of the packaged varieties that come from the grocery. When I think of nuts, I remember the pecans my dad and I used to pick up in the woods when I was a child. But do they go bad?
Nuts do expire and will become rancid after a certain length of time. How long they last depends on the kind of nut, when they were picked, whether they are still in their shell, and how they have been stored. Shelflife can be extended with proper handling and storage.
In the following paragraphs, we’ll discuss why nuts expire, how you can recognize when they have gone bad, and what you can do to extend their shelflife.
What Makes Nuts Expire?
Nuts expire because of the high oil content. Though the oil is a healthy unsaturated oil, when that oil is exposed to the elements, heat, light, and air, it begins to oxidize and becomes rancid. The nuts with the highest oil content are the first to expire.
How Can You Tell When Nuts Have Expired?
When nuts have spoiled, they begin to discolor and have a rank odor. If they appear a little darker than normal, a taste should tell the tale as nuts that have gone bad have a very strong, unmistakable and unpleasant taste. It’s a good idea to smell and taste nuts before using them in any recipe to make sure they are still good.
How Long Do Nuts Last?
How long nuts last depends on several things that include:
- The kind of nut
- Whether they are pre-packaged or home-grown or foraged
- When they were picked or fell from the tree
- Whether they are still in their shell
- How they have been stored
If you want to maximize how long your foods last, I recommend investing in some quality airtight storage containers. They are actually fairly inexpensive. Here are some that I recommend, found on Amazon.
Types of Nuts and How Long They Last
These are the most popular and most widely used nuts, and for an example, we are using pre-packaged shelled nuts for the length of time they last after the date listed on the package:
- Almonds Because they are loaded with antioxidants, whole natural almonds have a shelf life of approximately two years without a significant loss of quality if stored correctly.
- Brazil Nuts In addition to all the other health benefits, brazil nuts provide the recommended daily allowance of selenium. However, they should be eaten in moderation to avoid selenium toxicity. Because these nuts are high in polyunsaturated fats and may expire early if not stored properly, it is recommended that they are purchased unshelled and only shelled as needed. They can last 4-6 months.
- Cashews These nuts are always sold shelled because they contain a caustic resin used in making varnishes and insecticides that is found on the inside of the shells and must be removed before the nuts are fit to eat. They typically last up to 6 months.
- Chestnuts are hard to store and can only be kept unpeeled at room temperature for up to 1 week and in the refrigerator for 2 to 3 weeks in a bag with holes to allow air to circulate to them. After they are peeled and roasted, they can be stored in the refrigerator for just a few days but can be frozen in an airtight container for several months. The chestnut has been used as a food source by many civilizations since prehistoric times and was cultivated by the Japanese even before they started cultivating rice. It is a starchy nut that contains nearly twice the amount of starch found in potatoes and is excellent for making a gluten-free flour. And though starchy, the chestnut is lower in fat than other nuts. In the early 1900s, nearly 4 billion chestnut trees were growing in the eastern United States. The wood was rot-resistant, straight-grained, and widely used in construction. They were among the largest, tallest, and fastest-growing trees until a blight fungus wiped out nearly all of them. The chestnut blight has been called the greatest ecological disaster to strike the world’s forests in all of history.
- Hazelnuts Also known as filberts, hazelnuts are used in many confections and in making Nutella. As with other nuts, they will last longer if left whole, but if you want to chop, slice, or grind them ahead of time, they can be frozen for up to a year before use.
- Hickory Nuts The hickory nut is not a common nut and is available only if you know where a tree is located in the wild. But, this is one of the most flavorful nuts and tastes very much like a pecan. They are very difficult to crack and have a multi-chambered inner shell that looks similar to a walnut. Hickory nuts are the most calorie-dense plant food you can find in the wild with one ounce of the nutmeats containing 193 calories. They store well unshelled for several months in a cool dry area and for extended periods in the freezer.
- Macadamias Are native to parts of Australia and have a very high oil content. They are usually sold after they have been shelled and dried and often roasted, salted, and packaged. Macadamias should be eaten within a couple of weeks of purchasing or stored in the refrigerator for up to 6 months or the freezer for up to a year.
- Peanuts Even though peanuts are technically legumes and not nuts, they share similar storage problems because they are high in oil content. Unshelled raw peanuts can be stored in a cool dry pantry for up to 2 months, but shelled or unshelled will keep up to 1 year in a freezer.
- Pecans Shelled or unshelled Pecans should be stored in an airtight container either refrigerated or frozen because of their high oil content. Pecans stored unshelled in a freezer could remain good for up to 4 years.
- Pine Nuts Also called pignoli nuts, they come from pine cones and take up to a year and a half to mature. For that reason, pine nuts are quite expensive and can be kept in an airtight container in the refrigerator for 1 to 2 months. To extend their shelf-life, store pine nuts in a freezer bag or plastic container in the freezer for 3 to 6 months.
- Pistachios The best pistachios are split open at one end; those that are not split are immature and will not taste as good. Unshelled pistachios should be stored in a good plastic container in a cool dry pantry for up to 3 months, in a refrigerator for up to 6 months, and in a freezer for up to a year. Shelled pistachios should be kept in an airtight container in a refrigerator for up to 3 months, and do not freeze well.
- Walnuts (black and English) Walnuts go rancid when exposed to warm temperatures for an extended period of time. So, unless you are going to use them within a few months, store them in the refrigerator, if longer, in the freezer.
Shelf Life by Storage Method
Stored in the pantry:
- Chestnuts, 1 week.
- Macadamias, 2 weeks.
- Peanuts and Walnuts only last 1-2 months.
- Pistachios, approximately 3 months.
- Hazelnuts, 4-6 months.
- Pecans, 6 months.
- Cashews, 6-9 months.
- Brazil Nuts, 9-12 months.
- Almonds, 2 years.
In the Refrigerator:
- Chestnuts, 2-3 weeks.
- Pine Nuts, 1-2 months.
- Peanuts, Pistachios, Macadamias, and Walnuts, 4-6 months.
- All others up to 1 year.
In the Freezer:
- Chestnuts and Pine Nuts, 3-6 months.
- Brazil Nuts, Hazelnuts, Peanuts, Pistachios (Unshelled), and Macadamias, up to 1 year.
- Almonds, Cashews, Pecans, and Walnuts, up to 2 years.
How to Extend the Shelf Life of Nuts
All kinds of nuts stay good longer if kept in an airtight container like these (Click to see Amazon Listing), in a cool, dark area. Storing them in a closed container such as a canister or canning jar with a good lid would be ideal. And, all nuts last longer if left in their shells until ready to use.
Prepackaged nuts have a date printed on the package that they are best by, but that does not mean they are definitely bad after that date. A quick sniff and taste will let you know whether they are still good, but if that date has passed, it would be a good idea to go ahead and use them as soon as possible.
All nuts that are stored in a refrigerator or freezer should be placed in an airtight container to prevent them from absorbing odors from the other foods that are being stored. Plain old-fashioned or extra-thick freezer bags can be used for this.
Safe Storage Methods
Home-grown or foraged
Home-grown nuts still in the shell should be harvested as soon as they fall from the tree before they are partially eaten or carried away by squirrels or other scavengers and will usually last for a year if stored properly in a cool dry area such as a pantry or a root cellar and at least 2 years in the freezer. Once shelled, it would be safe to use the chart listed above for pre-packaged nuts.
Extra care should be taken for foraged nuts as you don’t really know whether they are this year’s crop or from an earlier season. I personally would taste a few to make sure most are good and go ahead and store in the freezer instead of taking a chance on pantry or root cellar storage.
Shelled or in the shells
All nuts should last at least twice as long when stored in the shells than after they have been shelled. When left in the shells, a box or burlap sack in a cool dry area make good storage options. After shelling, they last longer in an airtight container in the refrigerator or freezer.
Nuts are a healthy snack choice on any diet and add pizzaz to many recipes. According to the U.S. Food and Drug Administration, nuts as part of a diet that is low in cholesterol and saturated fat may help to reduce the risk of heart disease by adding dietary fiber, protein, and unsaturated fat.
No matter what kind or kinds of nuts you prefer, safe handling and storage practices can ensure that the nuts in your kitchen and pantry stay fresh until you are ready to enjoy them.
There is archeological evidence showing that nuts have been a part of the human diet since the beginning of history. Wild almond, prickly water lily, water chestnut, acorns, and pistachios were found in Israel from 780,000 years ago; tools called “nutting stones” were discovered in the United States and Europe dating from 4,000 to 8,000 years ago; pecans were discovered along with human remains in archeological sites in Texas from 6100 B.C.; and a manuscript discovered in China from 2838 B.C. indicated that hazelnuts were “among the five sacred nourishments God bestowed on human beings.
From their origins, nuts spread around the world with the early traders as they made their way along the ancient trade routes.
While different kinds of nuts provide different nutritional value, one ounce of mixed nuts contains 173 Calories, 5 grams of protein, 16 grams of fat, 6 grams of Carbohydrates, and 3 grams of fiber as well as Vitamin E, Magnesium, Phosphorus, Copper, Manganese, and Selenium.
The most common food allergy that is related to nuts is a peanut allergy in children. The symptoms of a peanut allergy can range from mild to life-threatening with the most common being:
- Skin reactions including hives, redness or swelling
- Runny nose
- Itching or tingling in the mouth and throat
- Digestive problems such as stomach cramps, nausea, vomiting, and diarrhea
- Tightening of the throat
- Shortness of breath or wheezing
In extreme cases, peanut allergy can cause food-induced anaphylaxis, a medical emergency that requires treatment with an epinephrine (adrenaline) injector and treatment by medical professionals.
Anaphylaxis symptoms can include:
- Constriction of the airways
- Swelling of the throat making it difficult to breathe
- A severe drop in blood pressure
- Rapid pulse
- Dizziness, lightheadedness or loss of consciousness
How to shell them
Most nuts have a hard shell that must be cracked with a nutcracker or a hammer and the nut picked out from within the shell, some nuts being harder to crack than the others. But the one exception is the peanut that is easy to crack with just the fingers and is not actually a true nut but a member of the legume family that includes peas and beans.
Can I eat expired nuts?
Even though some nuts when stored properly have officially reached their expired status, they may still be good and can safely be eaten as long as there is no obvious foul odor, discoloration, shriveling of the nutmeat, nor rancid taste.
In most cases, eating nuts that have gone bad will not cause any significant problems. But, in extreme cases, ingesting rancid nuts can cause severe inflammation of the digestive tract resulting in abdominal cramping, vomiting, or diarrhea. Seek immediate medical care if there is blood in your vomit or stool, or if you develop fever, difficulty swallowing, muscle weakness, or double vision.