Is It Safe To Eat Expired Peanut Butter?
Peanut butter is a popular spread and important staple in many households — and for good reason. It's rich and creamy and packed full of protein and important vitamins and minerals (via Healthline). It also has a pretty lengthy shelf life. Since peanut butter is high in fat, there's not a lot of moisture present in each jar, which means that bacteria is less likely to grow there. Most brands of peanut butter also contain stabilizers, like hydrogenated vegetable oils, and preservatives, which can help extend their shelf life and prevent bacterial growth.
As a result, commercial peanut butter brands can last quite a while. For instance, a jar of commercial peanut butter can last anywhere between six and 24 months if left unopened. However, this shelf life goes down to two or three months once it's opened. Natural peanut butter brands, however, tend to have shorter shelf lives since they don't contain any stabilizers or preservatives. Unlike commercial brands, natural peanut butter can last several months while still sealed and only one month once opened. However, refrigeration can briefly extend the shelf life of any type of peanut butter and help preserve freshness.
How to tell if peanut butter has gone bad
If you're not sure if your jar of peanut butter has gone bad, you can check the expiration date or do a quick taste test (via Live Science). Expired peanut butter tends to taste dry and rancid and gives off a foul odor. It may also appear darker in color. That's because peanut butter spoils and decays the longer it's exposed to oxygen. This is known as rancidification. Fortunately, however, this process can take quite a while. Generally speaking, rancidification doesn't occur until 9 to 12 months after purchasing and opening a new jar.
That being said, eating rancid and expired peanut butter isn't exactly dangerous. It's just unpleasant. "It won't hurt you if you eat it — it will just taste bad," Maribeth Cousin, a professor of food science at Purdue University in Indiana, told Live Science. "Some people actually eat rancid food without knowing it, depending upon their individual taste buds."