Peanut butter is considered one of the best nonperishable no-cook foods for emergencies.
It is easy to keep for your 30-day emergency food supply. However, it’s not always the best food to stockpile in large amounts.
If you want to store peanut butter long-term, here’s what you need to know about shelf life, which types of PNB last longest, and storage methods.
The best way to store peanut butter long-term is to get powdered peanut butter. It can last for up to 15 years unopened. You can also store some types of regular peanut butter long-term but, even if kept in ideal conditions, they will likely go rancid within a year or two. Natural peanut butter is not suitable for long-term storage.
Does Peanut Butter Go Bad?
Peanut butter is very high in fat and protein and has very little moisture. The low moisture it is very difficult for bacteria and fungi to grow in it. It is very uncommon for peanut butter to go bad in the sense that it would make you sick to eat. However, the fats in peanut butter do oxidize and will go rancid. The peanut butter will get a sour or bitter taste when this happens.
Peanut Butter Shelf Life
The USDA and National Peanut Board say that natural peanut butter will a few months in the pantry.
The shelf life of peanut butter with added stabilizers is longer: 6-9 months unopened in the pantry and 2-3 months once opened. Storing open peanut butter in the refrigerator will help it last a few months longer.
There are plenty of accounts of peanut butter lasting much longer than this, though. Many people have eaten peanut butter that was 5+ years old and had it taste fine. One man even ate peanut butter from WWII C-Rations and said it tasted fine. 1, 2, 3)
Is It Safe to Eat Expired Peanut Butter?
It is generally safe to eat expired peanut butter, even if it is very old. The peanut butter may have gone rancid and have a bad taste, but rancid food will not give you food poisoning. However, some people might get stomach problems from eating rancid food. Rancid peanut butter also won’t have as many nutrients as fresh peanut butter.
One potential concern is that peanut butter is sometimes contaminated with fungi. The fungi grow on the peanut butter and produce aflatoxin as a byproduct. There are also some rare cases where peanut butter was contaminated with Salmonella or E. coli.
Interestingly, multiple studies show that levels of bacteria and aflatoxin are lower in old peanut butter. The theory is that there isn’t enough moisture in peanut butter for the microbes to survive, so there are fewer of them in the older peanut butter. (5, , 6, 7)
Signs Peanut Butter Has Gone Bad
You will know that peanut butter has gone bad if it has a weird smell or sour taste. Bad peanut butter will also get darker.
It is normal for oil to separate from peanut butter in storage. This does not mean the peanut butter has gone bad. Simply stir the oil back into the peanut butter.
Also, be on the lookout for any signs of microbial growth, such as fuzz growing on the top. This is rare with peanut butter but could happen – especially if you put a dirty spoon into the peanut butter and introduced microbes into it this way.
Which Type of Peanut Butter Is Best for Long-Term Storage?
Powdered peanut butter is by far the best type for long-term storage. It is made by removing the fat and grinding the remaining proteins into a powder. You simply add water or oil to rehydrate it before eating.
Because there is almost no fat, powdered peanut butter won’t go bad as regular peanut butter will. Some brands, like Legacy Foods powdered PNB, have a shelf life of 10 to 15 years.
Read our guide to the best peanut butter powder.
How to Store Regular Peanut Butter Long-Term?
While it won’t last as long as powdered peanut butter, you can store regular peanut butter.
If you follow these guidelines, it should last around 2 years.
1. Choose the Right Type of Peanut Butter
Some types of peanut butter last much longer than others. For long-term storage, choose peanut butter which is:
- Stabilized with hydrogenated oil: Peanut butter stabilized with hydrogenated oil will last longer than ones stabilized with palm oil or corn oil.
- High Oleic: This type of peanut butter takes longer to oxidize.
- Full fat: Low-fat peanut butter may oxidize more slowly, but studies show that bacteria are more likely to survive in low-fat PNB.
- Chunky: Compared to smooth peanut butter, chunky PNB will oxidize slower.
Do Not Store Natural Peanut Butter!
No matter how it is stored, natural peanut butter will not last very long. After just one month in storage, natural peanut butter already gets rancid. By contrast, peanut butter with stabilizers added will last much longer.
If you really want to eat natural peanut butter, a better solution is to stockpile peanuts. Store them in Mylar bags with oxygen absorbers, and they can last up to five years. You would need a hand-powered mill to grind them into PNB during a power outage. (9, 10, 11, 12, 13)
2. Keep It Cool
Of all the factors which will make peanut butter go rancid, temperature has the biggest impact. Even a slight increase in temperature can increase how quickly PNB goes rancid. Try to keep the peanut butter in a very cool place and never let it get above room temperature.
Should You Freeze Peanut Butter?
Storing peanut butter in the freezer will keep it from going rancid. PNB could potentially last forever in the freezer. However, I still don’t recommend freezing your peanut butter. The main reason is that your freezer space is probably better used for more perishable foods or expensive foods like long-term coffee storage. Over time, your PNB would also absorb smells from the freezer. (16, 17)
3. Store Peanut Butter in Glass Jars
In terms of packaging for long-term peanut butter storage, glass jars are much better than plastic containers. They don’t allow as much oxygen into the PNB, so it will last longer.
Plastic containers aren’t completely air-tight. There are tiny holes in the plastic which allow air and moisture to pass through. In humid climates, the moisture level of peanut butter in plastic containers will increase and could allow bacteria to grow.
If you must buy PNB in plastic containers (it’s cheaper than glass and won’t shatter), choose PET instead of PP plastics. Peanut butter which comes in metallic pouches, is another good option. (18, 19)
4. Protect from Light
UV light speeds up oxidation. To keep peanut butter fresh longer, keep it in a dark place. Alternatively, you can put the peanut butter containers in paper bags to protect them from light. (20)
5. Keep It Upside Down
If stored long enough, even stabilized peanut butter will eventually separate. You end up with a layer of oil on top of the PNB. It can be messy to mix the oil back into the proteins. An easy solution is to store the peanut butter jar upside down. You’ll still need to stir it, but it won’t be as messy.