Look for small to medium size potatoes or yams with smooth, unblemished skin, all a uniform color. The sweet potato should be firm to the touch.

Sweet potatoes and yams are actually two different vegetables, but are often used interchangeably in recipes.

There are two varieties of sweet potato. One variety has a thin yellow skin and bright yellow flesh, while the other has a think orange skin and dark flesh. The latter variety is the sweet and moist; the former is closer to a white baking potato.

Sweet potatoes do not last as long as regular potatoes, no more than two weeks, but should be stored in the same manner: in a cool, dark place. Do not store yams or sweet potatoes in a refrigerator.