Nutrition: Potatoes pack a lot of energy (and calories) into their starchy insides. One medium potato contains about 170 calories. That translates to 26 calories per ounce. Potatoes are considered a good source of Vitamin C, Vitamin B6, potassium and manganese. If you keep the skin on, potatoes contain a lot of dietary fiber, too – 4 grams per medium potato.
Selection: Regardless of variety, look for spuds that are firm and smooth with no cracks or soft spots. Three medium russet potatoes equal about 1 pound and will make 2 cups mashed or two cups diced potatoes. When making mashed potatoes for a crowd, count on one medium potato per person.
Storage: Store potatoes in a cool, dry, dark place; don’t refrigerate. If bought pre-bagged, transfer the potatoes from their plastic wrap to a paper bag or cardboard box; they’ll keep fresh longer, usually at least two weeks. If potatoes begin to sprout, that’s an indicator that their storage space is too warm. Sprouted potatoes should be used as soon as possible, with the sprouts and any green spots trimmed away.
Preparation: Potatoes may be eaten peeled or unpeeled, but always scrub them clean first. Remove any eyes, sprouts and green spots as well as discolored areas of the flesh. Place peeled potatoes in cold water until ready to cook.
Starchy vs. waxy: Potato varieties are divided into two groups. As the name implies, “starchy” potatoes (think brown russet or Idaho) are low in moisture and sugar but high in starch. That starch breaks down when cooked, which makes these potatoes ideal for mashing, frying, baking and roasting. “Waxy” potatoes (such as red-skinned or fingerlings) have more moisture and sugar, but less starch. They tend to hold their shape when cooked.
White potatoes fall in between starchy and waxy, making them acceptable for all sorts of uses. Yellow potatoes (such as Yukon Gold) are another all-purpose potato with creamy, almost buttery flesh; that’s perfect for mashed potatoes but also good for baking, boiling and frying.
Potatoes with a difference: Purple or blue potatoes, native to Peru, have become a gourmet hit. These starchy potatoes cook like a russet, but keep their unusual color. They also contain more antioxidants than the white ones.