Should You Refrigerate Peanut Butter?

open jar of peanut butter
open jar of peanut butter

AtlasStudio / Getty Images

Whether you prefer crunchy or creamy, peanut butter fresh out of the jar is a delicious topping or ingredient that adds a truly defining flavor to nearly any snack or recipe. To keep it fresh, some people store this salt and sweet ingredient in their refrigerator, while others just keep it in their pantry. Should you actually refrigerate peanut butter, and what happens to it if you choose to stow it elsewhere?

Thanks to stabilizers, such as palm oil, that are found in processed versions of peanut butter, the product has a long shelf life; this means you do not need to refrigerate it, says Dr. Lisa Young, PhD, RDN, an adjunct professor of nutrition at NYU and the author of Finally Full, Finally Slim ($18.99, barnesandnoble.com). In turn, opened jars of peanut butter can last for two to three months in a cool and dry place. "To extend their shelf life past that time, it's okay to store in the fridge and it may last another three months or so," she explains. "The natural varieties (made just with peanuts and maybe salt), however, should be refrigerated when opened as the oils can go rancid quickly."

Related: 10 Peanut Butter Cookie Recipes That Are Sure to Delight

Do keep in mind that when you refrigerate natural peanut butter, the problem gets harder than it would at room temperature. "Some people like to put a serving in the microwave for a few seconds to soften it," Dr. Young says. "Also, when you don't refrigerate natural peanut butter, oil separation can occur, requiring you to mix it well upon using." The flavor does not change when refrigerating, though.

"When the oil gets rancid, it will give off an unpleasant smell," Dr. Young notes of when peanut butter begins to spoil. "If you see mold, you should also toss it." Steering clear of double dipping with a knife used for other ingredients, like jelly or jam, can help prevent cross contamination. "Also, when peanut butter is fresh it tends to be creamy; bad peanut butter tends to have a hard texture and may smell sharp if it turns," she adds.