The oils in the peanuts can go rancid if it's not kept cool. Likewise, if the label recommends refrigerating after opening, follow the instructions. (Also, if your peanut butter develops mold, toss it.
In general, commercial peanut butter does not need to be refrigerated. Opened jars of your everyday, processed peanut butter can sit in a normal pantry for up to three months after opening. Keeping the peanut butter at room temperature also has the added bonus of making it more creamy and spreadable when you use it.
If you buy all-natural peanut butter — these are the ones that are unrefined and likely made with just ground peanuts and salt — you'll want to store jars in the fridge after opening, since the oils can go rancid very quickly.
You'll be able to tell fairly quickly tell if your peanut butter has turned rancid: It will have a metallic, bitter and almost stale smell. It may also be darker and dried out in appearance. If it's natural peanut butter, it may be moldy. Any of these features signal it's time to throw away your jar of peanut butter.
Store the peanut butter at room temperature where it will keep for at least 2 weeks, or store in an airtight container or jar in the refrigerator, where it keeps for many weeks, and I've stored it for months.
Unopened conventional peanut butter: 6-9 months, no refrigeration needed. Opened conventional peanut butter: 2-3 months in the pantry, 6-9 months in the fridge.
WHAT ARE THE WHITE SPOTS/COATING ON THE SURFACE OF MY NUT BUTTER? If you find this in our Chocolate Coconut Peanut Butter,Chocolate Hazelnut, or Chocolate Almond Butter jars, it is called cocoa bloom. This happens naturally when the cocoa butter separates, solidifies and rises to the surface of the jar.
You Can Still Use Watery Peanut Butter
The good news is that you can still use your watery spread as long as it has not expired. If you dislike the watery texture, you can give it a good stir to mix the oil and butter before consuming or cooking with your spread.
If unopened, both smooth and crunchy peanut butter will keep for one year past its best before date whether stored in the pantry or fridge. Once it's been opened, both are good for three to four months in the pantry or six to eight months in the refrigerator past that date.
Information. You can keep peanut butter in the pantry for six to nine months (unopened) and two to three months (opened).
It's hard for peanut butter to spoil because it's mostly fat—that's what makes it taste so good. Natural peanut butter only contains peanuts and sometimes salt, and while some nut butters also contain oil, sugar or stabilizers, there's nothing there to add any water.
TLDR; don't store peanut butter in the refrigerator.
A jar of nut butter with low oxidative stability will begin to taste rancid, bitter, or pungent as time goes on. According to a study on the quality of stabilizer-free natural peanut butter during storage, natural PB kept at 10°C (50°F) began demonstrating loss in oxidative stability after just 12 weeks.
Peanut butter lasts months even if you leave it at room temperature, but it doesn't last forever. Stored long enough or in warm conditions, the fat from ground peanuts will eventually go rancid, and that's when you should toss it.
Grinding peanuts releases their oils. It's these oils that make peanut butter so creamy. Peanut oil is also a liquid at room temperature. So as the peanut butter sits, the oil rises and collects at the top.
This is a completely natural thing to happen for unstabilized, natural peanut butter. That layer on top is peanut oil. Simply stir it back in and your peanut butter has been 'restored'.
Lastly, some peanut butter brands add palm oil or hydrogenated oil (various plant-based oils) to make the peanut butter smoother or to keep it from separating in the jar at room temperature.
Yes, melt it. Just scoop a few tablespoons into a microwave-safe bowl, and nuke for 15 second intervals until it reaches a warm, sauce-like consistency. Then comes the real fun. You can pretty much eat it any way you'd like, but we listed eight of our favorite uses for melted peanut butter below.
Since oil and water don't mix, and peanut butter has a high oil content, there isn't much room in the mixture left over for water, explains Live Science. This can lead to naturally dry peanut butter, drying out more quickly due to its limited water content.
Peanut butter is not a hospitable environment for most bacterial growth, but spores of bacteria and some strands of Salmonella can still reside in the inhospitable environment of peanut butter. It is important to be aware that peanut butter can still be contaminated with Salmonella Typhimurium[2].
Small bits of peanut skins attached to the peanut when it is ground can cause these dark spots. The dark spots in our PB Bites look like chocolate chips. They are not peanut skins (which are reddish in color).
A new study from the University of Maryland does show that the thin, brown skins of peanuts are a mixed bag, as they may inhibit the growth of both beneficial and harmful microbes in the gut. The investigation also showed that peanut skins promote the growth of the harmful bacteria E. coli and Salmonella.
Peanut butter also provides many micronutrients and is a good source of vitamin E. Additionally, it contains the amino acid tryptophan, which the body needs to make serotonin and melatonin . Both melatonin and serotonin help regulate the sleep-wake cycle and promote quality sleep .