Bowl of peanut butter on top of a pile of peanuts
Does Peanut Butter Expire?
The lifespan of peanut butter partly depends on its composition. One containing only salt and peanuts lasts less than one with sugar, palm oil, and other preservative ingredients.
Peanut butter is made of legumes, like peas and lentils, and contains high amounts of unsaturated fat that quickly turns rancid when exposed to air, light, and high temperatures.
Once that saturated fat goes bad, the entire jar of peanut butter is ruined, and its flavor becomes unpleasant. Consuming stale peanut butter can even cause stomach problems.
However, proper storage can sometimes prolong its shelf life. As a good rule of thumb, an unopened jar of peanut butter can be safely stored in a pantry for six to nine months.
While an open jar of peanut butter should ideally be consumed within three months, storing it in a cool, dark, stable space in your fridge can keep it fresh for up to nine months.