Does Peanut Butter Go Bad? Here’s What You Need to Know.

Peanut butter is one of those kitchen staples I’ve only come to really appreciate as a grown-up. Yes, I can make a mean PB&J, but I can also add peanut butter to smoothies to boost their protein and taste, turn it into a sauce for a super-satisfying bowl dinner, or even add it to a pot of soup for a luscious finish. Needless to say, a jar of peanut butter gets used up pretty quickly in my kitchen.

This wonder ingredient isn’t impermeable to spoilage, though. While it is ideal for long-term storage (it is mostly fat with no water content), how you store it can impact its flavor and how long it will keep after its best-by date. Here’s what you need to know about peanut butter storage and how to tell if it has gone bad.

Believe it or not, peanut butter does have a best-by date on every jar — usually six to nine months from the date of manufacturing, if left unopened. The National Peanut Board recommends storing unopened jars in a cool, dark place, such as your pantry, and opened jars in the fridge for the longest shelf life. Don’t stress if you’ve been storing open peanut butter in the pantry, though — just know that you’ll want to use it with in a few months or it’ll lose its flavor.

Properly stored and uncontaminated by jelly or other spreads, peanut butter can last five to eight months past its expiration date. Oil separation isn’t a sign of spoilage; in fact it is totally normal, and you can just stir right back in. Odor and taste are the best indicators of spoilage, so give any jars past their expiration a good whiff — and when in doubt, throw any contaminated, off-smelling jars out.