Yams vs. Sweet Potatoes
Although they may look similar, yams and sweet potatoes come from two different plants. Sweet potatoes are most common in the U.S. Yams are not widely grown or sold here, coming from South America, Asia and Africa. But in the United States southerners often call sweet potatoes “yams.” The confusion is heightened by the fact that canned sweet potatoes are quite often labeled “yams.”
There are two varieties of sweet potatoes. The first, pale skinned with pale yellow flesh is not sweet after cooking and has a flavor resembling that of a baking potato. The other has dark orange skin and vivid orange sweet flesh. It cooks to a much lighter, sweeter consistency. I recommend the second variety.
The varieties of yams are too numerous to mention here. Chances are, the one you find in the store is a sweet potato.
Look for medium-size sweet potatoes with smooth unbruised skin. Sweet potatoes lose flavor when refrigerated before cooking. Do not store them for long periods of time, so buy only what you can use within a week. Sweet potatoes are a good source of iron, calcium and vitamins A and C.