Monday, November 25, 2013

When Is a Yam a Sweet Potato?


While enjoying the traditional Thanksgiving dinner, some people may ask, "What is the difference between yams and sweet potatoes?"  Are they the same by a different name? 

Many years ago orange colored sweet potatoes were introduced to the Southern United States. In an effort to distinguish these from the traditional white-fleshed potato, producers called them yams, which is the Anglicize African word, nyami.  Today, most of the starchy tubers consumed in the US and labeled as yams are in reality sweet potatoes. Yams and sweet potatoes however, are not the same; in fact, they are quite different from each other. 

As far as botanical order is concerned, they are at opposite ends. The sweet potato is a dicot, set in the morning glory family. Yams, on the other hand, are a monocot, closely related to grasses. The sweet potato, whose sweet and moist flesh varies in color from white to yellow and orange, is native to South America; the skin is typically smooth. In contrast, yams are dry and starchy and rather bland. While yellow or purple in color, the skin is rough and a bit shaggy. Yams are native to North Africa and Asia. They range in size from that of a small potato up to 150 lbs. Yams are a primary agricultural crop in West Africa, where 95 percent of the world's yam crop is grown. 

Garnet, Jewel, and Beauregard are orange fleshed sweet potatoes that  masquerade as yams in the local supermarkets.