Are Sweet Potatoes and Yams the Same Thing?

For many of us, the terms sweet potato and yam may be interchangeable. The truth is, generations of Americans have been getting it wrong. Sweet potatoes and yams are not the same. They are two separate foods that aren’t even from the same family. We’ll tell you when the confusion exactly began, and explain, once and for all, what the difference is between sweet potatoes and yams.

Why the Confusion?

If yams and sweet potatoes are different from each other, what caused their names to be used interchangeably? The answer: marketing. In the 1930s, a new sweet potato variety that was larger and sweeter, with soft orange flesh, was cultivated by Julian C. Miller at the Louisiana Sate University Agricultural Center. In order to differentiate it from the sweet potatoes that already existed (smaller, drier and with white or yellowish flesh), sweet potato growers decided to call the new variety a yam—a word that is rooted in the West African words nyam, nyami or enyame, which mean “to eat.” Communities of enslaved Africans were the first to refer to the sweet potato as a yam, as it reminded them of the ones they ate in Africa.

So, What Is a Yam?

A yam is the modified stem or tuber of a tropical vine called Dioscorea batatas. Although they may look similar to sweet potatoes, they are an entirely different species (yams belong to the Dioscoreaceae family and are related to grasses and lilies, and sweet potatoes belong to the morning glory family) and not even remotely related. Yams grow in subtropical and tropical climates like Africa, South America and the Caribbean and are commonly found in cuisines from those areas. There are more than 150 different yam varieties in the world.

What Is a Sweet Potato?

A sweet potato is the storage root of Ipomoea batatas. They grow in warm, temperate climates as well as in tropical regions. They are native to the Americas but grown in many parts of the world. Thousands of different varieties exist today.

Uses for Yams vs. Sweet Potatoes

Yams and sweet potatoes can both be prepared by roasting, steaming, boiling or frying. Substituting real yams in a sweet potato dish would be like using potatoes instead of sweet potatoes in the recipe—it would work, but the end result would taste very different.

Bottom Line

A yam is a tuber. A sweet potato is a root. Yams tend to be more cylindrical and have scaly, bark-like skin. Sweet potatoes tend to have a more tapered shape and may be firm or soft with thinner skin. Generally, sweet potatoes taste sweeter than yams. You will more readily encounter sweet potatoes during your regular grocery run, but if you spot a yam, which may be labeled “sweet potato,” you’ll know the truth.

FAQs

What is the difference between sweet potatoes and yams?

Now that you know a little more about sweet potatoes and yams, it’s easy to see that they’re actually two different vegetables! They look different, they taste different, and they grow differently, too. They might just have more differences than they do similarities!

Is a yam healthier than a sweet potato?

Both sweet potatoes and yams are nutritious, albeit completely different vegetables. They are both good to eat as a part of a healthy diet and neither is particularly nutritiously superior to the other. That being said, sweet potatoes contain more vitamin C, vitamin A, fiber, and protein.