Although you shouldn’t put potatoes in the fridge, potatoes will still keep the longest when stored in a cool, dark place—specifically somewhere that has a cold temperature of about 50°F and 90 to 95 percent humidity, like, you know, a temperature- and humidity-controlled root cellar.
Oh wait, I don’t have a root cellar?
Here are a few storage tips;
1. Keep Them out of the Sunlight (but Not out of Sight).
Don’t store potatoes out in the open on the countertop. Keep them in a drawer, in a basket, in a closet, in a paper bag, or in a bamboo vegetable steamer—anywhere that's dark—and they should last for one to 2 weeks. A clear plastic bag, like that kind that potatoes are packaged in, are actually not ideal for storing spuds. Potatoes are plants, after all. If they see sunlight, they will do their photosynthesis thing and turn green, and eventually wrinkle and rot.
And remember, out of sight, out of mind—keep them in a trafficked-enough part of the pantry so you don’t forget about them.
2. Make Sure They Still Have Airflow
Either transfer your potatoes to a paper or mesh bag, like the Five Two Organic Cotton Reusable Produce Bags or a well-ventilated container. (They will be releasing carbon dioxide and water in the form of vapor, so things can get a little too damp.) If you’d like to keep them in the plastic bag they came in, make sure it’s well-perforated and that the top isn't tightly sealed.
3. Don’t Store Them Next to Your Onions
We touched on this earlier, but let’s get into the nitty gritty. It’s tempting to toss both your potatoes and onions together in a basket in your pantry and be done with it—after all, they both like to be stored basically the same way. But resist temptation, because keeping them together (along with potatoes and avocados, potatoes and bananas, and potatoes and apples) might encourage your potatoes to sprout.
4. Avoid Warm Spots
Even if you don't have a cooler storage location than your kitchen, take care to avoid the warmest spots in the room: Don’t store your potatoes next to the oven, under the sink, or on top of the fridge.
When warmer than their ideal storage temperature, potatoes will start to sprout, but colder isn’t necessarily better either. In On Food and Cooking, Harold McGee explains that when kept at colder temperatures (i.e. your refrigerator), “their metabolism shifts in a complicated way that results in the breakdown of some starch to sugars.” This means potatoes stored in the refrigerator will taste sweeter over time, and when cooked they are more likely to come out an unappetizing shade of brown.
Signs That Potatoes Have Gone Bad
There are a few easy things to look for if you’re wondering, “have my potatoes gone bad?” Mold, black spots, and soft spots are easily tells. Dr. Benjamin Chapman, an associate professor and food safety specialist at North Carolina State University, also recommends avoiding consuming potatoes that are wrinkled, soft, or shriveled. It’s not necessarily harmful to eat, but think of it like eating any other rotten fruit, such as bananas or apples. The flavor and texture will not be at their best and it’s just all-around unappetizing.
As for green potatoes, Dr. Chapman says that’s a sign that the spuds have been exposed to too much light and will give off a bitter flavor and can even be irritating to the digestive system.
Now that you're a pro at storing potatoes.