How Long Do Peanuts Last?

You’ve bought a big bag of peanuts in the supermarket, and once you got home, you realized you’re not sure how long peanuts last. Or how to store them, so they keep as long as possible.

Or perhaps there’s an old bag of peanuts you found organizing the pantry. There are no labels with dates, and you only have a vague idea of when you’ve bought it. That’s where knowing exactly how to tell spoiled peanuts from good ones come in.

Either way, you need to learn a thing or two about the shelf life, storage, and spoilage of peanuts. And that’s what this article is all about.

Unshelled peanuts on a tablespoon
Unshelled peanuts on a tablespoon

How Long Do Peanuts Last?

Let’s start with some rough estimates from the FoodKeeper App (FK). These are the following:

  • at room temperature, shelled peanuts should keep quality for four weeks, while unshelled for four months
  • both in-shell and shelled peanuts last about a year in the fridge, and two years in the freezer

The said periods are only estimates. And if you take good care of the legumes (peanuts are not technically nuts (WIKI)), you should get a couple of extra weeks or even months.

What the app doesn’t mention, but you need to know, is that roasted and/or flavored peanuts don’t last as long. So if you’ve prepared a big batch of curry roasted peanuts, or opened a large pack, finish them within a week or two, or refrigerate.

Peanuts in a bowl closeup
Peanuts in a bowl closeup

How long can you store roasted peanuts? Unfortunately, that’s impossible to tell. If you’ve bought them pre-packaged, check the label for an estimate. If you’ve done the roasting yourself, stick with a week or two at room temperature, or go with cold storage. If you’re yet to roast them, do as much as you need for the next couple of days.

Speaking of pre-packaged peanuts, make sure what the label says. The date there is also an estimate, but it gives you a good idea of how long the peanuts should keep quality.

Long story short, pantry storage is good enough for short term (especially for unshelled peanuts), while the fridge or freezer is your go-to option for the long term.

Of course, to make sure peanuts last for as long as possible, you should store them properly. And that’s precisely what we’re going to cover next.

Opened peanut
Opened peanut

How To Store Peanuts?

As we already covered, freezer, refrigerator, and pantry are your options when it comes to storing peanuts. And as you know, the warmer the temperature, the shorter the shelf life.

If cold storage is what you opt-in for, things are super straightforward. Pack the peanuts in an airtight container or freezer bag and into the fridge or freezer. That’s about it. You might consider adding a label with a date if you know they will sit there for a long time.

For room temperature storage, it depends on whether you have in-shell or shelled peanuts on hand.

For the former, a large bowl or a mesh bag is the way to go. I usually go with the bag and put it where it’s convenient to grab a couple of nuts and shell them. Make sure they don’t sit near any sources of heat, though.

Shelled peanuts need some extra protection. Basically, you need to provide everything that the shell (that’s already gone by now) does. That means an airtight container or bag, and a dry and dark spot with stable temperature.

Once again, if your peanuts are roasted or flavored, go with cold storage if you want them to taste their best for more than a couple of weeks.

Whole peanuts in bag
Whole peanuts in bag

How To Tell If Peanuts Have Gone Bad?

When it comes to spoilage, peanuts are quite similar to nuts. The usual suspects include:

  • insect infestation
  • mold (on the shell or kernel)
  • discolored and dried out kernels
  • rancidity

How to tell if peanuts are rancid? I’m glad you asked. Look for changes in odor and taste. The peanuts might smell like chemicals, rancid butter, or smell sour. When it comes to flavor changes, rancid peanuts usually have a harsh and bitter taste. If either is there, discard the peanuts.

However, if your peanuts seem to be okay, but maybe a bit stale, you can freshen them. For that to happen, all you need to do is to roast them.

Peanuts in a glass bowl
Peanuts in a glass bowl

How To Roast Peanuts

If you’re thinking about roasting your somewhat stale peanuts, consider flavoring them as well. Extra spices can give the peanuts a much-needed flavor boost, and the prep usually takes only a couple of minutes. If you need some inspiration, Google for curry roasted peanuts.

Before we get to roasting instructions, there’s one thing you should know. Letting peanuts sit in too hot temperature for too long oxidizes the polyunsaturated fatty acids (PUFAs) in them (HL). And oxidized fats are no good (we eat foods rich in antioxidants to combat oxidation).

While peanuts don’t have as much PUFAs (WIKI) as e.g., walnuts, you shouldn’t go willy-nilly about this. Where’s what Healthline (HL) suggests to do to get the flavor benefits and keep oxidation to a minimum:

  • preheat your oven to about 284°F (140°C)
  • roast shelled peanuts in a single layer for about 15 minutes
  • let them cool a bit before eating
Whole peanuts closeup
Whole peanuts closeup

Since peanuts are rather small, check them after about 10 minutes of roasting. They might be done already. If you’re coating them for extra flavor, a minute or two more than usual might be needed.

If you don’t finish the roasted peanuts the same day you prepared them, and aren’t sure when your next session of gorging in peanuts will take place, consider refrigeration to retain the flavor for longer.


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