Peanut butter is a very popular sandwich spread in some countries. And it’s tempting to think that it lasts forever. So does peanut butter go bad?

We expect the shelf life of peanut butter to be quite long, and it certainly is. But can it really go bad?

Like most other foods, peanut butter can go bad, but it happens very rarely. It can go bad if it has been contaminated in any way. If it has not been, you must remember that it loses its flavor over time.

Keep in mind that its shelf life (the time when its quality is best) depends mostly on how you store it. If you store it well, you can eat or use it before it starts to change flavor.

How to preserve peanut butter

Storing peanut butter is easy. The first thing to remember is that the peanut butter jar should always be closed with its lid when not in use. Peanuts (and therefore peanut butter) contain a lot of oil (fat), so oxygen can alter the flavor of peanut butter.

This process is called rancidification: oxygen breaks down the structure of the fat, which changes the taste and smell of the product. The longer you expose peanut butter to air, the worse it will taste.

For store-bought, unopened peanut butter, store it in a cool, dark place, preferably in your pantry.

Once the container is opened, you can keep it in the pantry if you plan to use the contents of the jar in a couple of months. For long-term storage, keeping opened peanut butter in the fridge is the best option.

Peanut butter opened at room temperature slowly loses its flavor. When you move it to the fridge, the process continues, but slows down considerably. The only drawback to storing peanut butter in the fridge is that it becomes much firmer. And that means it no longer spreads quickly and easily.

If you make your own peanut butter and do not use stabilizers, it is best to keep it refrigerated.

How long does peanut butter last?

Probably all jars of peanut butter have a “Best before”, “Best before”, or similar label. That is nothing more than the manufacturer’s information that the product must be of the best quality for such a period of time.

It does not mean that it will go rancid or taste bad after that time. It rarely happens. Unopened peanut butter can last for months or even years after the expiration date, depending on the amount of preservatives it contains.

Opened peanut butter, if stored in the refrigerator, can keep well for at least a few months after the date on the package.

If you want to know how long peanut butter lasts after the expiration date, there’s no easy answer. It depends on its ingredients and how you store it.

When it comes to homemade peanut butter, the shelf life depends on the recipe you use. In most recipes, the authors mention how long it lasts.

If you don’t add any perishable ingredients to your homemade peanut butter, it should last at least a month, probably much longer.. If you were looking for a quick homemade peanut butter recipe.

Please note that the dates in the table are approximate. And often peanut butter will last even longer.

How do you know if peanut butter is bad?

Because peanut butter contains a lot of fat and a minimal amount of water, bacteria and fungi don’t have much of a chance to live and grow in it.

Oxygen seems to be the biggest factor that can influence peanut butter (if it hasn’t been contaminated in some way). And as said before, it doesn’t make peanut butter bad, it just alters its flavor.

Be aware that when you store peanut butter for a long time, the oil may separate and you will see it on top of the contents of the container. The same thing happens with almond butter. It is perfectly normal; you can stir the spread and the peanut butter will be good again.

A few words of caution: If you notice your peanut butter has a strange (or off) odor, its flavor is drastically altered, or you simply see something wrong with it (besides oil separation), throw it out. It is always best to prevent than to cure.

If your peanut butter doesn’t taste as good as it used to, that doesn’t mean it’s spoiled. If you can’t find any signs of spoilage, it’s most likely safe to eat.

Eating it will most likely not harm you, but you may want to throw it away due to its quality. It depends on you. Some people don’t mind that peanut butter tastes a little different than usual, others do.

Peanut Butter FAQ

What about natural peanut butter?

I am not mentioning natural peanut butter in this article, and that is on purpose.

The term “natural” is not clearly defined, so each brand’s natural peanut butter has its own set of ingredients. Normally, natural peanut butter contains at least 90% peanuts, but other than that, it depends on each brand what else is in it. The healthiest peanut butters out there are those with one or two ingredients: peanuts and salt.

So how do you preserve natural peanut butter? The same way you store “regular” peanut butter: in the pantry, tightly closed. Plain peanut butter does not need to be refrigerated unless directed by the producer.

Does peanut butter and jelly go bad?

I think everyone knows that a peanut butter and jelly sandwich goes bad.

If you leave it outside, it will probably take a day or two before mold starts to grow. If you put it in the fridge, it can stay there for a long time (think days) without spoiling. And by not spoiling, I mean it will still be safe to eat.

The problem is that the quality of a peanut butter and jelly sandwich will deteriorate much faster. The bread will get soggy or stale, and you may want to throw it away after a day in the fridge.

Of course, you can experiment with different types of bread and amounts of peanut butter and jelly, and you might come up with a combination that lasts a bit longer.