HAVANA, Ill. — As the holiday season approaches, it seems appropriate to discuss the issue of sweet potatoes versus yams. Rhonda Ferree, horticulture educator with University of Illinois Extension, said that, officially, a sweet potato is never a yam, but sweet potatoes often are referred to as yams.
Sweet potatoes are yellow or orange tubers that elongate into ends that taper to a point. There are two types of sweet potatoes, which creates the confusion over yam versus sweet potato.
The paler-skinned sweet potato has a thin, light yellow skin with pale yellow flesh that is not sweet and has a dry, crumbly texture similar to a white baking potato. The darker-skinned variety — which most often is called “yam” in error — has a thicker, dark orange to reddish skin with a vivid orange, sweet flesh and a moist texture.
Ferree said that most people probably never have seen a true yam. The true yam is the tuber of a tropical vine and is not even distantly related to the sweet potato.
The yam is a popular vegetable in Latin American and Caribbean markets and slowly is being introduced here. The true yam actually is even sweeter than the sweet potato, and the tuber can grow over seven feet in length.
The yam tuber has a brown or black skin that resembles the bark of a tree and off-white, purple or red flesh, depending on the variety.
Another root vegetable commonly used in Central America is called cassava or yucca.
“It differs from the yucca plant we grow here,” Ferree said. “When we were in Costa Rica, the starchy cassava root was peeled and boiled like potatoes.”
And, interestingly enough, when it is dried to a powdery, or pearly, extract, this root makes tapioca.
On another note, sweet potato vines are popular for their ornamental value as ground covers, hanging baskets, in planters and even in bottles of water in the kitchen. The ornamental vine’s tubers are edible, but are reported to have a bland taste.
In the end, it doesn’t really matter what you call it. Regardless of whether you call them yams or sweet potatoes, enjoy them often — they’re healthy and tasty choices for your kitchen table.