The ideal temperature to store potatoes is 42 to 50 degrees. Most refrigerators are set at 37 degrees, which is a few degrees colder than this. Room temperature is usually much higher, at 65 to 70 degrees. If you do not have a cool location, you can store potatoes in the fridge. Put them in a perforated plastic bag to retain humidity and provide ventilation. Do not store potatoes with apples.
You can store potatoes at room temperature for up to a few weeks. They will become soft and may begin to sprout if you store them at 65 to 70 degrees for more than a few weeks. Warm temperatures also make them more susceptible to disease. Storing potatoes in the fridge causes the starch in them to convert to sugar, which makes them turn darker if you fry them. They are safe to eat but will not look like golden fries. Boiling or baking does not affect the color. Do not freeze potatoes.
Humidity and Darkness
Potatoes need darkness, humidity and ventilation. Ideal conditions are 90 to 95 percent humidity. If you store potatoes in the fridge for more than a few weeks, check the bag to be sure they are not molding due to lack of ventilation. Light causes potatoes to accumulate chlorophyll and turn green. You can cut off small portions of green, but discard potatoes with large amounts of green because they can contain toxic compounds. Store them in dark-colored bags or a cardboard box.
Storing Harvested Potatoes
Do not wash harvested potatoes before you store them. A root cellar or storage cabinet that can be maintained at the ideal temperature and humidity is best for long-term storage of large quantities of potatoes. You can improvise with an extra refrigerator set to the ideal temperature of 42 degrees. Potatoes will keep for several months at this temperature before they begin to sprout. Take them out of the fridge four to six weeks before planting time to encourage sprouting.
If you are buying potatoes and do not have a place to store them under ideal conditions, purchase only the quantity you will consume in a few weeks. If you are growing potatoes, consider how you will store your harvest and prepare the location in advance. If you use a root cellar or other method of storing loose potatoes, be sure to store potatoes and apples in separate compartments. Apples give off ethylene gas, which causes potatoes to sprout. Potatoes also cause apples to lose their flavor.