Does Peanut Butter Need to Be Refrigerated?

Peanut butter is a kitchen essential, yet opinions vary on whether it belongs in the fridge or the pantry. The key to understanding if peanut butter requires refrigeration lies in the type you use—natural or conventional. We spoke with experts for their guidance on the best storage practices for maintaining its freshness.

How to Store Peanut Butter

There are two main types of peanut butter. One is made with stabilizers that keep the oil from separating (that's the regular, spreadable stuff), while the other is formulated from roasted peanuts (this is typically called natural peanut butter). The type you have will dictate your storage method.

Natural Peanut Butter

Natural peanut butter, which is made of ground, roasted peanuts, should be refrigerated immediately after purchase. "Because it does not have preservatives or stabilizers, it is best refrigerated to keep it fresh and to prevent the oil from separating out," says Margarethe A. Cooper, PhD, assistant professor of practice and Victor P. Smith Endowed Chair in Food Safety Education at the University of Arizona. "The separated oil in unrefrigerated natural peanut butter is more likely to become rancid sooner, leading to unpleasant taste and texture."

Natural peanut butter is also more at risk for mold growth; refrigeration can help prevent this. 

Conventional Peanut Butter

Peanut butter with preservatives and stabilizers that keep it from separating doesn't need to be refrigerated. Instead, you can store conventional peanut butter in a cool, dry place, such as a kitchen pantry or cabinet. "Conventional peanut butter does not need to be refrigerated because it has added oils that stabilize it to keep the oil from separating out and to extend its shelf life," says Cooper.

Additionally, conventional peanut butter has low water activity, which means microbes generally can't grow in it.

How Long Peanut Butter Lasts

No matter where you store your peanut butter, both natural and conventional varieties have a shelf life.

Conventional Peanut Butter

Generally, an unopened jar of conventional peanut butter can last in your pantry for six to nine months, while an open jar can last for about two to three months. "To extend its shelf life past that time, it's OK to store in the fridge," says Lisa Young, PhD, RDN, an adjunct professor of nutrition at New York University. "It may last another three months or so."

Natural Peanut Butter

An unopened jar of natural peanut butter should be stored in the refrigerator immediately after purchase, where it can last for up to 12 months. "Once opened, refrigerated natural peanut butter is best consumed within three to four months of opening," says Cooper.

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Signs Peanut Butter Has Gone Bad

There are some telltale signs a jar of peanut butter has spoiled, like if it smells or tastes bad. "When the oil gets rancid, it will give off an unpleasant smell," says Young. This is typically caused by the oil separating out, which may give the peanut butter a dry appearance. "Oil separation in natural peanut butter is more likely since it does not have stabilizers, and when the oil is exposed to oxygen this leads to oxidative rancidity, causing the characteristic unpleasant odor and flavor," says Cooper. Additionally, you should throw away peanut butter if you see any mold in the jar.

Cooking With Peanut Butter

Conventional peanut butter is typically preferred in baking. It has a smoother consistency than natural peanut butter and is easier to incorporate into other ingredients. Here are some of our favorite recipes using peanut butter.

Peanut Butter Swirl Brownies: These decadent brownies combine sweet and salty, swirling chocolate with the roasted flavor of peanut butter.

Peanut Butter and Jelly Bars: The classic combination of PB&J comes together in a sweet way in these great bars. Top them with chopped peanuts for great texture.

Peanut Butter Stuffed Pancakes: An unexpected crunchy peanut butter center makes these unique pancakes a breakfast hit. Top them with strawberries or bananas for a winning flavor combination.

Peanut Butter Cup Tart: A chocolate crust and chocolate ganache envelop a creamy peanut butter filling in this rich dessert.

Peanut Butter No-Bake Cookies: Stir your mixture in a saucepan, then drop the dough by tablespoons onto parchment paper for these easy-to-make cookies.