Red-skinned potatoes (as well as round whites) are considered "waxy;" slice into one, the flesh looks translucent and firm. Though not all red potatoes are "new" (they can only be considered that if they were picked young) red potatoes, like all true new potatoes have a low-starch content and so can be used interchangeably. When boiled and sliced, they will hold their shape, which makes them perfect for potato salad; their low starch content means they only lightly absorb salad dressing, which makes a potato salad that's chunky, rather than creamy. Red potatoes may also be mashed, but be careful: they easily turn gluey if over mashed; use them when you want a more rustic, lumpy mash smashed with a spoon.
1 medium red potato - 5 oz. = 1 cup medium (1/2 inch) dice
Try New potatoes or Ruby crescents.
Try to buy loose (instead of in plastic bags) so you can easily evaluate them. They should feel firm and heavy for their size and never soft, wrinkled, or blemished. Avoid those with even a hint of green, which indicates the presence of solanine, produced when potatoes are exposed to light. This mildly poisonous alkaloid has a bitter flavor that can cause an upset stomach. If your potatoes turn green after you get them home, peel off all traces of the colored flesh before cooking.
Wash gently under cool running water. Leave the tender skins on to contrast with their white interior, or peel off a spiral band of skin before cooking.
Potatoes should be stored in a dark, cool (ideally 45° to 50°F), dry place. Never refrigerate raw potatoes. If the temperature is too cold, some of the potatoes' starches will turn into sugars. Not only does this taste unpleasant, but the extra sugars also lead to overbrowning during cooking. If a potato winds up in cold storage, you can convert the sugars back to starches by storing it at room temperature for a few days.