Yams or Sweet Potatoes?

Expert advice from Food Editor Karen Scales

Food Editor Karen Scales

Food Editor Karen Scales

DEAR KAREN: What's the difference between yams and sweet potatoes? This time of year, I see both in grocery stores and wonder if they're the same thing.
—N.W., Cleveland, Ohio

With Thanksgiving just around the corner, you'll likely see signs for both yams and sweet potatoes in stores. They are similar in many ways and, therefore, often confused with one another. But they are actually from different plant species.

True yams are not widely marketed and are seldom grown in the United States. They are similar in size, shape and color to sweet potatoes, but yams contain more natural sugar and have a higher moisture content. They're also not as rich in vitamins A and C.

There are many varieties of sweet potatoes, but the two most common commercially are a pale sweet potato, with a light yellow skin and flesh, and the more common darker-skinned variety. Americans often label that variety as a "yam" to distinguish it from the lighter sweet potato. So, chances are, what you see in your grocery store are most likely sweet potatoes, regardless of how they're labeled. However, if they are yams, they may be substituted for sweet potatoes in most recipes.