Yams vs. sweet potatoes: The straight dirt
Contrary to popular belief, a sweet potato by any other name is not a yam. Don’t call those bright orange tubers we enjoy every Thanksgiving yams. They’re sweet potatoes. Although the names are often interchanged, the two are very different and not even related.
Sweet potatoes are members of the morning glory family. The skin color varies from light to rusty orange with an oblong shape that tapers at both ends.
Cut inside a sweet potato and you’ll expose flesh with hues from almost white to orange, red and even purple. Those with an almost white flesh are firmer when cooked. The softer version, with the bright orange flesh, are the ones that make Thanksgiving casseroles fluffy and so tasty.
Although the health benefits of sweet potatoes are often masked with butter, brown sugar and marshmallows, they are actually a terrific source of fiber and vitamins. They’re high in vitamins A, B5 and B6, as well as thiamin, niacin, riboflavin and, owing to their orange color, carotenoids.
Yams are a starchy edible root that is a relative of the lily family. True yams originated in South America and Africa and have a rough, scaly brown skin. The vegetable is long, cylindrical and often has “toes” that extend off of one end.
These root vegetables can also grow large. Very large. When harvesting yams, they are often referred to as 1-, 2-, or 3-men yams, referring to how many men are needed to lift one up. Yes, some yams grow to over 7 feet in length.
The flesh of a yam is white, starchy and rather dry. If you want to purchase true yams, steer your car toward a market that specializes in Latin American or African food. They are seldom found in a traditional grocery store.
Why the confusion?
The orange-fleshed variety of sweet potatoes has been referred to as yams since colonial times. African slaves referred to the root vegetable by the African word “nyami.” The name later was Americanized to “yam” and it stuck.
Supermarkets began labeling the white-fleshed sweet potato as a sweet potato while naming the softer, orange-fleshed variety of sweet potatoes “yams.” The U.S. Department of Agriculture now requires labels with the term “yam” to be accompanied by the words “sweet potato.”