What Is the Difference Between Sweet Potatoes and Yams? Types, Characteristics, and Easy Sweet Potato and Yam Recipes

A sweet potato (Ipomoea batatas) is a root vegetable belonging to the morning glory family and native to tropical regions of the Americas. It’s smooth, outer skin ranges in color from dusty orange-brown, to vibrant red, to light yellow-beige, while the insides range from an immediately recognizable orange flesh to purple and even pale white. Sweet potatoes are the official vegetable of North Carolina.

There are over 400 varieties of sweet potato around the world, including:

1. 1. The Korean purple sweet potato, which features a chestnut flavor when boiled.
2. 2. The Creamsicle sweet potato, whose pale white outer skin hides a sweet, sugary orange interior.
3. 3. The Okinawa sweet potato, a Japanese varietal with a vibrant violet flesh.
4. 4. The Beauregard sweet potato, one of the most familiar sweet potatoes on US shelves, with a rusty red outer flesh.

A yam is an edible tuber from the flowering plant of the genus Dioscorea, native to Africa and Asia, with 600 varieties worldwide. Wild yams, or Dioscorea villosa, are native to North America but their roots are not consumed: instead, their leaves and vines are used as a medicinal herb.

Most frequently found in international markets, true yams can be identified by their large size and blackish-brown, bark-like skin (though not unlike the sweet potato, they also may also have white, purple, and reddish flesh). Yams are a staple food in Caribbean diets, and a purple yam called ube is a cornerstone of Filipino cuisine, primarily in desserts. Yams bear a slight visual similarity to cassava (also known as manioc), a woody shrub often ground into flour or used to make tapioca.

While they may sometimes look alike, sweet potatoes and yams are indeed different root vegetables. They do, however, share some commonalities:

• Richness of flavor. Both root vegetables feature in sweet and savory preparations where they are consumed, acting as a flavorful base for ingredients like maple syrup and marshmallows as well as herbs and spices.
• Preparation method. Like most root vegetables, sweet potatoes and yams are best roasted until crispy on the outside and soft on the inside. They can also be boiled or steamed, but can turn mushy.

There are a few key differences between sweet potatoes and yams:

• Texture. Yams tend to be starchy and dry, with more of a mild taste compared to the sweeter, creamier flesh of a sweet potato.
• Nutritional value. Sweet potatoes are a rich source of fiber and a multitude of vitamins and minerals, including iron and vitamin C. They’re also high in beta-carotene, a beneficial antioxidant that delivers vitamin A once digested. Yams have lower levels of beta-carotene, but are an excellent source of energy, thanks to its suite of B vitamins like B6 and B1. They can also help to lower cholesterol levels.

The answer has to do with the history of both vegetables in the United States.

Hundreds of years ago, when slaves were brought to the U.S. from Africa, they referred to American sweet potatoes as “nyami,” which translates to “yam” in English. This is because local sweet potatoes reminded them of true yams, a food staple they knew in Africa. To add to the confusion, the familiar dark-skinned, orange-fleshed Beauregard sweet potato cultivar was only introduced to the U.S. several decades ago. In order to set it apart from paler-skinned, native sweet potatoes, producers of the time decided to label them “yams.”

Today, the term “yam” is now more of a marketing term for producers to distinguish between the two types of sweet potatoes—in fact, true yams are quite uncommon in U.S. supermarkets.

Outside the U.S., other common vegetables are frequently mistaken for yams, including:

• Oca. In New Zealand, a local sweet potato varietal called the oca is often called a yam.
• Taro. The tropical root plant taro is often mistaken for yams in Malaysia and Singapore. Though it’s similar to yams in size, shape, and starch content, taro actually belongs to the arum family.

Here are four winning recipes to help you get to know sweet potatoes as an ingredient.

1. 1. Healthy sweet potato “toast” recipe: A popular substitute for bread among the wellness set is a thick slice of roasted sweet potato with various toppings. Toast slices in a toaster or oven until lightly browned, then top with everything from lemony mashed avocado and sliced radishes, almond butter and chopped almonds, or even lox, red onion, and capers.
2. 2. Homemade oven sweet potato fries recipe: Wash sweet potatoes and slice lengthwise into halves, then again into 1-inch wedges. Toss with olive oil, salt, and pepper, and roast at 400°F for 15-20 minutes, or until golden brown and easily pierced with a fork. This can also be done with diced sweet potato for an easy addition to grain bowls or kale salad.
3. 3. Easy sweet potato pie recipe: This cousin of pumpkin pie is popular in the American South, and features all the familiar notes of cinnamon and nutmeg, with a slightly firmer filling traditionally provided by garnet sweet potatoes. Boil 1 pound of whole sweet potatoes until soft, about 30 minutes. Let cool, and remove the skin. In a large bowl, mix the sweet potato with ½ cup unsalted butter at room temperature until well-combined; stir in 1 cup sugar, ½ cup milk, 2 eggs, ½ teaspoon ground nutmeg, ½ teaspoon ground cinnamon, and 1 teaspoon vanilla extract. Beat until mixture is smooth and transfer to an unbaked 9-inch pie crust. Bake at 350°F for 50 minutes, until tester comes out clean.
4. 4. Candied sweet potatoes recipe: In a saucepan over medium heat, melt ½ cup brown sugar with ¼ cup butter, ¼ cup water, and a pinch of salt. Pour over sliced wedges or cubed sweet potato (about 4 medium) and place in a baking dish; cover with foil and bake at 350°F for 30 minutes. Remove the foil and cook 10 minutes more, or until potatoes are caramelized, crisp and golden brown.

If you’re fortunate enough to get your hands on true yams, here are three recipes to try.

1. 1. Ube pancakes recipe. In a large bowl, combine 1 ¼ cup flour, 1 teaspoon baking soda, 2 teaspoons baking powder, 4 tablespoons superfine sugar, and ½ teaspoon salt. Add 2 cups buttermilk and 1 beaten egg, and mix until well combined. Add 1 cup grated purple yam, and mix. Cook pancakes in a lightly oiled pan over medium heat for 3 minutes each side.
2. 2. Simple, roasted white yams. Halve yams lengthwise and place cut side up on a baking sheet or in a roasting pan. Drizzle with olive oil, season with salt, pepper, and fresh herbs like thyme or rosemary, then roast at 400°F for 15-20 minutes, or until golden brown.
3. 3. Battered yam fries recipe. Combine 1 cup all-purpose flour, 1 cup rice flour, and 2 teaspoons salt in a large bowl. Whisk in 2 cups club soda until batter comes to preferred consistency. Meanwhile, lightly cook yams in boiling water for 5-10 minutes, until just tender. Let cool and slice into wedges, then dredge in batter and fry in vegetable oil over medium-high heat until crispy and cooked through. Remove from pan, season with salt, and repeat with remaining yams.

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