Here's How Long That Jar Of Peanut Butter Will Last After Opening

Peanut butter is a staple in my kitchen, and it's likely that you keep the spread well-stocked, too. Whether you prefer the classic smooth option or you go for the chunky kind (my personal favorite), you might be wondering just how long your peanut butter will stay fresh once you've cracked open the jar. Thankfully, the National Peanut Board has kept the answer relatively simple.

According to the NPB, a marketing arm of the United States Department of Agriculture, unopened peanut butter can last 6 to 9 months without refrigeration, but, once opened, you'll only have 2 to 3 months to eat it. However, you can extend an opened jar's life by popping it in the fridge, where it can last another 3 to 4 months.

So, you've got plenty of time to enjoy some good old-fashioned peanut butter and jelly sandwiches — or PB and mayo, or maybe even Hemingway's famous PB and onion, no judgment here.

Natural peanut butter, my preferred type due to its simpler ingredients list and lack of added sugar, is a bit more of a hassle to maintain. Natural PB is just peanuts and salt, and usually comes in the jar with a healthy layer of oil at the top. You're meant to stir the contents of the container and then refrigerate it to help the peanut butter keep its consistency. FoodSafety.gov says that the natural variety of peanut butter can last 3 to 4 months after opening if stored in the fridge per instructions on the jar. It'll last for a year in the fridge if you don't open it, but who wants to wait that long?

Still, let's say you actually did forget about your jar of peanut butter — how do you know it's gone bad? Peanut butter will go rancid if it expires due its the high fat content. In processed peanut butter, check the contents for a bitter or even metallic smell. If that's paired with a darker appearance or harder texture, you know it's no good. If for some reason it doesn't smell or look bad, but it tastes bitter, consider it spoiled. For natural peanut butter, it's even more straightforward: it can grow mold when it goes bad.

Here's hoping your PB never gets to that point. There are innumerable peanut butter recipes to try, from sandwiches to sesame noodles. You just can't take peanut butter on a plane.