Sweet Potato or Yam?
Source: Rhonda Ferree, University of Illinois Extension educator, horticulture
As the holiday season approaches, it seems appropriate to discuss the issue of sweet potatoes versus yams. Rhonda Ferree, University of Illinois Extension educator, horticulture, says that officially a sweet potato is never a yam, but that sweet potatoes are often referred to as yams. Sweet potatoes (Ipomoea batatas) 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 which is not sweet and has a dry, crumbly texture similar to a white baking potato. The darker-skinned variety (which is most often called “yam” in error) has a thicker, dark orange to reddish skin with a vivid orange, sweet flesh and a moist texture.
The people in one of the highlands of western New Guinea are reported to subsist almost entirely on sweet potatoes. One medium (5” x 2”) boiled, peeled sweet potato provides more than twice the recommended daily allowance of Vitamin A for an adult, 36% of the Vitamin C and a good amount of other vitamins and minerals. Sweet potatoes may be boiled, baked, browned, fried and candied. They can be used to make biscuits, breads, muffins, pies, custards, cookies, and cakes.
Ferree says that most of us have probably never seen a true yam. The true yam is the tuber of a tropical vine (Dioscorea sp) and is not even distantly related to the sweet potato. The yam is a popular vegetable in Latin American and Caribbean markets, and is slowly being introduced here. The true yam is actually 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 which resembles the bark of a tree and off-white, purple or red flesh, depending on the variety.
On another note, sweet potato vines are becoming increasing 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.