The only times you should put peanut butter in the fridge

Peanut butter is one of those pantry staples that are great for apocalypse survivors and mini-fridge-sharing college students alike. You can hang on to an unopened jar for up to 9 months, and even after it's been opened, you can keep commercial peanut butter in your pantry for up to three months (via National Peanut Board). There are some circumstances, however, when you're going to have to refrigerate it. 

If you have superhuman willpower, however, and can keep peanut butter around for more than three months without finishing it, then it's time to refrigerate. The National Peanut Board says that the jar will last 6 to 9 months in the fridge. You should also refrigerate commercial peanut butter if you're staying in a hot, humid area. Dietitian Alex Lewis, RD told Women's Health, "The oils in the peanut butter can go rancid after a few weeks if you're in a hot climate."

If you're someone who likes to forgo Jif and Peter Pan for natural, freshly ground peanut butter, you're going to want to refrigerate it. According to the Food Network, you should always refrigerate all-natural peanut butter because the oils it's made with can spoil very quickly. One exception: If you're the type who polishes off jars in just a few weeks, you'll be fine keeping the peanut butter in a dry, cool area.

How about other nut butters?

Similar to peanut butter – though a sealed jar can last up to two years at room temperature – almond butter lasts 2 to 3 months in your pantry once opened (via ExtraCripsy). You can make it last for twice as long if you keep it in the fridge. Also like peanut butter, Epicurious suggests refrigerating natural almond butter and says that the same rules for storing natural versus commercial jars apply for cashew, hazelnut, and macadamia nut butter. 

How about nut-free peanut butter substitutes? Maybe you have a kid in elementary school, or maybe there's a nut allergy in your household. According to the website, Wowbutter, a soybean-based option is good for 1 to 2 years after production unopened and for 90 days in the pantry after opening. Sunflower seed butter, on the other hand, only lasts 6 months unopened, according to EatByDate, and though an open jar can survive for a little while in the pantry, refrigerating it will extend its shelf life to 6 months. 

As a general principle with nut and seed butters, keep them in the pantry if they're commercial, and you're going to finish them within a couple of months. Refrigerate them if they're all-natural, if you're going to take a while, or if you're in an unusually muggy environment.