You know potatoes will keep the longest when stored in a cool, dark place—specifically somewhere that's around 50° F. So just toss them down in your root cellar and call it a day. But we don't have a root cellar—do you?
In case, like most people, you don't have a root cellar, here are some potato storing strategies to keep in mind:
Keep them out of the sunlight
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.
Make sure they still have airflow
Either transfer your potatoes to another more ventilated container or if you keep them in the plastic bag they came in, make sure it’s well-perforated and the top isn't tightly sealed.
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 might make your potatoes sprout faster and taste more like onions.
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 or under the sink.
Warmer than their ideal storage temperature will make potatoes 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.