Does Peanut Butter Go Bad?

I’m an expiration date optimist. After a quick sniff test, I categorize most items in the “still good” category for maybe longer than I should. But while I keep a close eye on the items in my refrigerator, I operate on the loose assumption that foods in my pantry will last …forever. Peanut butter is one of those foods.

Yet despite my pantry-based optimism, peanut butter does go bad. Its high fat content makes it rich and delicious, but that fat will eventually go rancid. The good news is it takes a long time to get to that point. An unopened jar of commercial peanut butter can last for six to nine months in your pantry, while an opened jar can last for two to three months, according to the U.S. Department of Agriculture (USDA) respectively. The National Peanut Butter Board — also suggests these ranges.

Natural peanut butter has a shorter shelf life, about three months less than commercial peanut butter, because it doesn't contain preservatives or stabilizers. It’s best to store it in the refrigerator, even before opening, where it can last about three to four months.

How to tell if peanut butter is has gone bad

Start with the good old sniff test before you taste it. If your peanut butter has gone bad, you’ll notice a metallic smell coming from the jar. Additionally, spoiled peanut butter may appear darker in color. You can also check the texture: If it doesn't spread well and shows signs of cracking, hardness, or breakage when you try to spread it on bread for a PB&J,  it may have gone bad. Any or all of these signs for both natural and commercial peanut butter means it's time to pick up a new jar.

But oil separation doesn’t always mean it’s gone bad. With natural peanut butter, you may notice separated oil that floats to the top of the jar don't panic, this doesn’t mean it’s gone bad. Unlike commercial versions, natural peanut butter doesn’t have stabilizers added to it; the oil separation is normal. Just give it a quick stir (even if it says ‘no stir’) and you’re good to go.

How to store peanut butter

Commercially made peanut butter, like Jif or Skippy, does well in a pantry because it's out of direct sunlight and remains relatively cool and dry. Natural peanut butter is also fine stored in your pantry, but it will last much longer if you keep it in your refrigerator — especially after it’s been opened.