Does Peanut Butter Go Bad?

Compared with other spreads, peanut butter generally has a long shelf life.

This is because peanut butter is high in fat and has a relatively low moisture content, which provides unfavorable conditions for bacterial growth (1).

There are other key factors that can influence the shelf life of peanut butter.

For starters, how it’s manufactured plays a significant role in its shelf life.

Most commercial peanut butters use stabilizers, such as hydrogenated vegetable oils or palm oil, as well as preservatives like sodium benzoate to help extend their shelf life (2, 3).

The addition of stabilizers helps to prevent oil separation and improves the texture and appearance, while preservatives, including sodium benzoate, help combat microbial growth.

Because of the addition of stabilizers and preservatives, commercial peanut butters may last 6–24 months in the pantry if left unopened, or 2–3 months once opened. Placing it in the fridge can extend its shelf life beyond this (4).

On the other hand, products labeled as natural peanut butters must contain at least 90% peanuts. They have a shorter shelf life because they generally lack preservatives and stabilizers. However, some natural peanut butters may contain stabilizers to prevent oil separation.

In general, natural peanut butters without stabilizers can last for several months in the pantry unopened, or up to a month once opened. However, they may last up to a year in the fridge unopened, or 3–4 months in the fridge once opened (4).

Many natural peanut butter products that contain only peanuts and salt state to “refrigerate after opening” to preserve freshness.

The shelf life of natural peanut butters can vary considerably among brands due to the addition of different ingredients, so it’s important to check the best-by date on the packaging.

Powdered peanut butter is a new alternative made by pressing the majority of the natural oils from roasted peanuts and grinding the nuts into a powder. Most labels state that they can last 10–12 months unopened, or 4–6 months once opened.

However, powdered peanut butter may last longer than the listed best-by date if unopened and stored in a cool, dry, dark place, such as the pantry. This is because it has less fat than regular peanut butter, which means it’s less prone to reacting with oxygen.

SUMMARY

In the pantry, commercial peanut butters may last 6–24 months unopened, or 2–3 months once opened. Natural peanut butters may last several months unopened, or up to a month once opened. Placing peanut butter in the fridge can extend its shelf life.

Most packaged peanut butters have expiration dates — also called best-by dates — printed on the container, which indicates how long the product will stay fresh.

However, these labels aren’t compulsory and don’t ensure the product’s safety. That means your peanut butter may still be safe to eat beyond its best-by date (5).

The best ways to tell if your peanut butter has gone bad are by sight and smell.

While fresh peanut butter is naturally soft and creamy, bad peanut butter may have a hard and dry texture. It may also have a dark brown appearance, compared with its usual light tan color.

Additionally, if it smells more sharp, soapy, or bitter, it likely has gone bad.

Moreover, if your peanut butter tastes slightly sour instead of nutty, it may have gone bad as well.

Keep in mind that oil separation is normal for natural peanut butters because they may lack stabilizer ingredients. It’s not a sign that the peanut butter has gone bad.

It can be more difficult to tell whether powdered peanut butter has gone bad, but changes in smell, texture, and taste are good indicators.

Summary

Peanut butter that has gone bad may show signs like a change in texture to dry and hard; changes in aroma, including a loss of aroma; and a more sour or bitter taste.

To ensure that your peanut butter lasts longer, it’s important to store it properly.

Although it doesn’t need to be refrigerated, cold temperatures ensure it lasts longer. If you prefer not to refrigerate your peanut butter, aim to keep it in a cool, dark place, such as the pantry.

It’s also important to always close the jar of peanut butter tightly. Exposing peanut butter to air for too long may cause it to go rancid faster.

Additionally, make sure to use clean utensils when you use peanut butter. Used or dirty utensils could introduce unwanted bacteria through cross-contamination, which can promote spoilage.

Powdered peanut butter should also be stored in a cool, dry, dark place, such as the pantry. If you mixed powdered peanut butter with water to make creamy peanut butter, you can store this in a tightly covered container in the refrigerator for up to 48 hours.

Summary

It’s ideal to store peanut butter in cool, dark places, such as the pantry or fridge. Make sure to handle peanut butter with clean utensils to prevent cross-contamination, and to close the jar tightly to limit air exposure.

Peanut butter generally has a long shelf life.

In the pantry, commercial peanut butters may last 6–24 months unopened, or 2–3 months once opened. Natural peanut butters lack preservatives and may last several months unopened, or up to a month once opened.

However, certain brands of natural peanut butter may last longer due to the addition of stabilizers, so it’s important to check the best-by date.

Powdered peanut butter is best stored in a cool, dark, dry place, such as the pantry, and the best-by date states it can be stored up to 12 months. However, it likely can last longer than this, as it has properties that make it less likely to go rancid.

Proper use and storage, as well as refrigeration, can extend the shelf life of any type of peanut butter considerably.

Signs that your peanut butter has gone bad include a change in texture to dry and hard; changes in aroma, including a loss of aroma; and a more sour or bitter taste.