Does Peanut Butter Go Bad?

Peanut butter is a very popular sandwich spread in a few countries. It’s tempting to think that it lasts forever. So, does peanut butter go bad? Most of us expect that shelf life of peanut butter should be pretty long. But does it really go bad? Similarly to most other foods, peanut butter can go bad, but it happens very rarely. Peanut butter can go bad if it’s been contaminated somehow. If it wasn’t, you should still remember that it loses its taste with 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 should be able to consume it before it even starts to change its flavor.

How To Store Peanut Butter

Storing peanut butter properly is important. Fortunately enough, it’s easy to do that properly. The first thing you should remember is that the jar of peanut butter should be always closed with its lid when you’re not using this sandwich spread. Peanut butter contains a lot of oils (and therefore fat) so oxygen can influence its taste. This process is called rancidification – oxygen degrades fat’s structure which changes the flavor and smell of the product. The longer peanut butter is exposed to air, the poorer its taste will become.

If you make your own peanut butter and you don’t use any stabilizers, you should keep it in the fridge. If you’ve got a commercially manufactured one, keep it in a cool, dark place, preferable in the pantry. After you’ve opened the container, it’s best to store it in the pantry and, after a few months of storing, transfer it to the fridge. If you wish to, you can store peanut butter in room temperature but it’ll cause the flavor loss and oil separation to progress faster. Storing it in the pantry for most of the time is convenient – peanut butter spreads quickly and easily.

Peanut Butter French Toast Sandwiches

Image used under Creative Commons from Bobbi Bowers

Shelf Life Of Peanut Butter

Probably all peanut butter jars have a ‘Best By’, ‘Use By’ or a similar label. That’s just manufacturer’s information that the product should be of best quality for such period of time. It doesn’t mean that it’ll go rancid or taste awful after that time. In fact, it rarely does. Your homemade peanut butter should be of best quality for at least half a year. As long as your commercially bought peanut butter is closed, it should stay fine for two years and at least half a year once it’s opened. If you’ve prepared (or bought) some peanut butter protein bars, I’m pretty sure you don’t care about their shelf life because you’ll consume those bars within the next couple of days!

How To Tell If Peanut Butter Is Bad

Since peanut butter contains a lot of fat and (therefore) a minimal amount of water, bacteria and fungi don’t have much place to live and grow in peanut butter. Oxygen seems to be the biggest factor which can influence peanut butter (if it hasn’t been contaminated somehow). As I’ve said earlier, it doesn’t really make peanut butter go bad, it just alters its taste.

Please bear in mind that when peanut butter is stored for a long time, oil might separate and you’ll see it on top of container’s contents. That’s perfectly normal, you can stir the contents and the peanut butter will be fine again. Word of caution here – if you’ll notice that peanut butter has strange (or off) odor, its flavor is altered drastically or you just see that it’s something wrong with it (something besides oil separation), discard it. It’s always better to be safe than sorry.

If the peanut butter tastes just not as good as it used to, that doesn’t mean it’s spoiled. If you can’t find any certain signs of spoilage (as described earlier), it’s fine. Eating it won’t hurt you, but you might want to discard it due to its quality. It’s up to you. Some people don’t mind peanut butter tasting a little different from usually, some people do.

As you can see, peanut butter can go bad, but it’s pretty unlikely for that to happen. It’s far more probable that it’ll simply lose its taste and you’ll have to discard it due to its poor quality. Peanut butter protein bars also can go bad (how fast they go bad depends on the recipe), but in most cases you’ll use them before they can even start to lose their taste.