True Yams Hard to Find in North American Grocery Stores

— Written By N.C. Cooperative Extension

Article written by Jessica Strickland, Extension Agent-Horticulture

Q: Is there a difference between sweet potatoes and yams?

A: During the Thanksgiving Holiday along with turkey you will probably have a lot of side dishes made up of all kinds of vegetables. One of those vegetables was probably sweet potatoes or yams. It is commonly asked whether sweet potatoes and yams are the same thing or not?

Typically when you purchase a can that says yams, you can look at the ingredient list and find that the first ingredient listed is sweet potatoes. In the United States yams and sweet potatoes are used interchangeably but refer to what are really sweet potatoes. On the other hand though, there is a plant called a yam that is not even closely related to a sweet potato. Yams are more closely related to lilies while sweet potatoes are more closely related to morning glories. Sweet potatoes are really not even related to our regular white potatoes which are more closely related to tomatoes, peppers, and eggplants.

A true yam is rare to find in grocery stores because it is a plant that is mostly grown and consumed throughout the tropics. Yams are grown in Africa and South and Central America. True yams are a starchy, dry tuber that is scaly in appearance and typically has white flesh. They are best apt to tropical climates and do not perform well in our climate.

Sweet Potatoes on the other hand are native to the tropics of Central and South America and are commonly grown in the United States. A sweet potato is a sweet, moist storage root with smooth, thin skin and typically has orange flesh.

Since sweet potatoes and yams are really two completely different plants, why has the names long be used interchangeably? Christopher Columbus was reportedly the one who was responsible for spreading true sweet potato plants throughout the New World, including the present-day United States. The name confusion came about when producers and shippers wanted to distinguish them from the traditional white potatoes. The African word “nyami”, which originally referred to the starchy, edible true yam, was adopted in its English form “yam”. The name yams stuck with our true sweet potatoes from then on. The U.S. Department of Agriculture does require that any use of the word “yam” to describe sweet potatoes must be accompanied by the name “sweet potato.” So, a close look at the label will tell you that what is being advertised as yams are really sweet potatoes.

Even though there is the name confusion associated with sweet potatoes, we have to thank Columbus for helping in the spread of sweet potatoes into the United States. Most sweet potatoes are grown in the southeastern area of North Carolina with North Carolina being ranked as one of the top sweet potato producing states.

So even though you know that instead of candied yams you are really eating candied sweet potatoes, you have to admit that those sweet potatoes make a pretty tasty dish that we don’t want to pass up during our holiday meals.

Learn More!
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Jessica Strickland
Extension Agent
Horticulture
North Carolina Cooperative Extension
Wayne County Center
P. O. Box 68
Goldsboro, NC 27533
E-Mail: jessica.strickland@waynegov.com
Phone: 919-731-1520
Fax: 919-731-1511
https://www.ces.ncsu.edu/wayne