Yam or sweet potato? The surprising difference

A rose by any other names is a rose … but a yam is not a sweet potato. It might be possible you’ve never tasted a real yam unless you shop in specialty grocers that stock imported produce.

Those “candied yams” you serve on Thanksgiving are probably sweet potatoes. A true yam is starchier and drier; plus 90 percent are imported from the Caribbean, Africa or Asia.

Interesting fact: Nigeria exports 70 percent of the world’s yams. They are rough, scaly and very low in beta carotene. The many varieties range drastically in size. 

Most sweet potatoes are grown in the U.S. Depending on the variety, they vary from white to orange and even purple flesh. The orange variety was introduced to the U.S. several decades ago. To distinguish it from the white variety we were used to, producers chose the English form of the African word “nyami” and labeled them “yams.”

The USDA requires that orange-colored sweet potatoes always be labeled “sweet potato,” but most people still think of sweet potatoes as yams regardless of their true identity. They can be either “firm” or “soft.” Firm sweet potatoes remain firm when cooked, while the soft type becomes moist.

Sweet potatoes have more vitamin A, surprisingly, than yams; but yams have more potassium.   

The biggest difference in cooking is the need to cook yams longer to remove toxins. Unlike sweet potatoes, which can be eaten raw, yams should always be cooked because they contain many naturally occurring plant toxins. They must be peeled and cooked thoroughly to remove these bitter proteins.

This holiday season, why not try an alternative casserole to replace sugar-soaked candied “yams"?

Simple Sweet Potato Casserole

Serves 6

Start to finish: 35 minutes


  • 1 sweet potato
  • 1 Tablespoon coconut oil, melted
  • 1/2 cup walnuts or pecans
  • 1/4 cup brown sugar
  • 1/4 cup coconut flakes

Preheat oven to 350°. Wash sweet potato well. Slice it long ways into flat oval pieces. Place each piece onto a cookie sheet; paint with melted coconut oil. Bake for 20 minutes or until the sweet potato is soft. In a sauté pan, toss together the nuts, brown sugar and coconut over medium heat until sugar melts and adheres to the nuts. Serve your sweet potato warm topped with the nuts.