A daily fixture of my morning routine is standing over the kitchen counter with a half-full jar of peanut butter, dolloping a serving atop my breakfast and spooning another serving (or two) into my mouth (for protein and healthy fats, of course). Often, I find myself in the same routine before bedtime, but usually with chocolate involved. The jar begins and ends each day at the ready, perched front and center on the snacks shelf of my nut-product-abundant cupboard.
This happy routine was shaken by a recent heated debate in the Epicurious Slack room. Staff writer Emily Farris proclaimed that āanyone who refrigerates peanut butter is a monsterā and supported her claim with the fact that natural peanut butter is much harder to stir when cold. Editor Emily Johnson countered that she refrigerates natural peanut butter and keeps her Jif in the cupboard. This debate made me wonder: Which Emily is correct? Does peanut butter need to be refrigerated?
The quick answer is that it depends on a few different factors, which are not often spelled out on the jarās label. The first factor to consider is which type of PB youāre buying.
Should you refrigerate one kind of peanut butter but not another?
Peanut butter generally has a long shelf life; itās high in fat and low in moisture, meaning pretty unfavorable conditions for bacterial growth. Some brands are made to have an even longer shelf life with the addition of stabilizers like palm and hydrogenated oils, as well as preservatives like sodium benzoate. Once opened, these peanut butters are usually fine to store in a cool, dry cupboardāthe stabilizers prevent oil separation and these preservatives help to combat microbial growth.
The story can sometimes be different with natural peanut butter, which is typically unrefined and made with just ground peanuts and salt (and sometimes not even salt). With all-natural peanut butter, oil separation can occur, requiring you to mix well before consumption. As Epiās Genevieve Yam explains, āThe oils in nuts and seeds can go rancid, so I see why some people would refrigerate nut or seed butter, but in my household we go through peanut butter so quickly that itās not necessary.ā
Mark Overbay, cofounder of small-batch nut butter brand Big Spoon Roasters, contends that widespread use of stabilizers found in most nut butters has led to a belief that peanut butter does not have to be stirred, and if it does, you need to refrigerate it. He says that this isnāt always true, and that refrigeration isnāt necessary for his products even though they forego preservatives. Like Yam, Overbay asserts that especially if youāre consuming it quickly, you can keep your jar in a cool, dry place rather than refrigerating it.
How long does peanut butter last?
According to The National Peanut Board, an unopened jar of peanut butter can last six to nine months at room temperature. Once opened, they say that it can last two to three months in the pantry before you should move it to the fridge, where it can maintain quality for another three to four months. Foodsafety.gov agrees that most commercial peanut butters that contain stabilizers will last two to three months at room temperature after opening (for natural peanut butters, they recommend refrigerating to preserve the quality). In either case it is wise to go by the expiration date on the jarās labelāand just like with hot sauce, if a label on the jar says to refrigerate, you should refrigerate it.
If Iām not refrigerating my peanut butter, where should it go in my kitchen?
Overbay says that if youāre keeping your peanut butter out of direct sunlight and in a cool, dry place, it will stay delicious for many months. This means keeping the jar away from sources of heat like an oven. Another trick he shares is to store your jar upside down. That way, the oil separates toward the bottom of the jar so that when you turn it right side up, itās easier to stir back in without making a mess. āWith natural peanut butter, oil separation is just going to happen and thatās okayāall you have to do is stir it back in and enjoy,ā he says.
Does climate affect whether you should refrigerate peanut butter?
If you live in a hot or humid climate, you may not have a ācool, dry placeā for storing your peanut butter and might want to consider refrigerating it (even if the jar says itās not necessary) to extend shelf life. Epiās Joe Sevier is a committed peanut butter refrigerator: āmy New York kitchen gets too hot,ā he says. āThings that ādonāt go rancid if you eat them fast enoughā always go rancid.ā If your kitchen is cooler and less humid, though, the oils in the jar will not go rancid as quicklyāso if you go through a jar in less than a month, itās fine not to refrigerate!
What are the downsides to refrigeration?
Cold peanut butter often gets harder than it would at room temperature, making scooping it out of the jar seem impossible. If you do prefer the taste or texture of peanut butter at room temperature, you can scoop out what you need and let it warm at room temperature or even microwave it before spreading.
Should you be careful about using a knife that also touched jam?
Yes! It is important to never double-dip or stick jelly-smeared knives into a jar of peanut butter, since this can introduce bacteria. If you start to notice any mold or smells, you should toss the jar.
When should I throw out a jar of peanut butter?
In addition to the appearance of mold or a sharp or soapy smell, peanut butter thatās gone bad might taste sour or bitter and might darken in color. Besides using clean utensils, this can be prevented by making sure to close the jar tightly to minimize air exposure.
Do the same rules apply to peanuts?
Yes! Peanuts, shelled or unshelled, can last in a bag or sealed container for a month or two, according to the National Peanut Board. While their high oil content can help to hinder mold or bacteria, those oils can still undergo chemical reactions, like oxidation, which affects the nutsā flavor. Storing them in the fridge can extend their shelf-life for up to four to six months. Another pro tip: You can freeze peanuts to keep them fresh for up to a year.
