How Long A Jar Of Peanut Butter Really Lasts After Opening

Peanut butter is a delicious, satisfying, and often healthy (depending on how natural it is). But that's not all it can boast. Peanut butter is known for its long shelf life. The question is, just how long are we talking? Especially once we open that jar — does peanut butter really last as lengthy a time as we think it does, and how can we make sure it lasts the longest it can while being safe and tasting fresh?

According to the National Peanut Board, peanut butter that's been opened can last two to three months in your pantry, and six to nine months in your refrigerator. You may have wondered whether you should be refrigerating peanut butter, since it's often associated with the pantry. As with many foods, peanut butter benefits from those lower temperatures, which inhibit bacterial growth and therefore spoilage. Refrigeration is especially vital for natural peanut butters because they don't have preservatives and have fewer stabilizers. 

Brands will tell you whether their peanut butter needs refrigeration on their labels — for example, Kirkland's peanut butter says it should be refrigerated after opening. It's worth noting that refrigeration isn't necessary before you open the peanut butter. The USDA and National Peanut Board say unopened jars last six to nine months in your pantry. This is likely where peanut butter gets its reputation as a cabinet staple with staying power.

The National Peanut Board's advice on the shelf life of peanut butter refers to the spread in general. But since we know natural peanut butter has fewer stabilizers and doesn't have preservatives, making it an even more necessary candidate for the refrigerator, does it actually have a different period of time for which it's still good?

According to Southern Living, natural peanut butter can last for about three weeks unrefrigerated, as long as it is still kept somewhere cool and dry. Remember, you want conditions that don't encourage bacterial growth, which warm temperatures and moisture do. In the fridge, natural peanut butter can last up to two months. You can even freeze it to get six months out of it. Processed peanut butter, meanwhile, can last three to six months in the same kind of cool, dry spot, or nine months refrigerated.

You should also, of course, refer to the peanut butter's expiration date. When in doubt, have an idea of what to look for in expiring peanut butter. This includes a sour or metallic smell, and a color that's changing whether it's getting lighter or darker. While you'll always see some oil on the top of natural peanut butters because they don't have emulsifiers to blend in the peanuts' own oil, spoiling peanut butter may get extra oily. Its texture could become slimey, or in some cases, too hard to spread.