Ah, sweet potatoes and yams! If I had a dime for each time I’ve observed the confusion between them, I would be a wealthy woman.
Does it make a difference? Probably not in practical terms: in Minnesota, unless you seek out the gigantic tuber known properly as a yam in a West African market, you will never see one. Yams grow in tropical countries, they’re bigger than most dogs, and you’re as likely to find one here as you are a fruit bat or a wildebeest. These things become gigantic—a 60-pounder (the great Asiatic yam) was heaved from the ground of Malaysia, and that seems to have broken the record. Nutritionally, they don’t offer much but pure carbohydrate fuel. Their taste is bland, a neutral background against which to play lively, spicy vegetable and meat stews.
Contrast those bigger-than-your-arm tubers with the slender little sweet potato, which comes originally from South and Central America. This winsome creature has since found a happy home throughout the Americas, the Caribbean, the Pacific, Asia, Africa, Europe, and the Near and Middle East. There’s a good reason for its popularity: it has long been selectively bred for sweetness, and you know how we humans feel about sweetness. Its flavor ranges quite widely, and it can be grown just about anywhere, including greenhouses in the far North. The yellow and orange ones fairly bristle with vitamin A. Their flesh is commonly velvety and lends itself to puddings, custards, and soups. Lately, of course, the sweet potato has shone as the rock star of fries. Its only relative of any size is the very peculiar manroot (I. letpophylla) of the West Coast. It looks like a pod from Invasion of the Body Snatchers, and it seems designed to be avoided.)
So how could two tubers so dissimilar in appearance and taste possibly be confused for each other?
The answer began with the African slave trade. The first Africans transported to the Caribbean and North and South America came from southwestern Africa, where they had cultivated true yams. On Caribbean and North and South American plantations, the enslaved people were fed and told to cultivate sweet potatoes. Because of its resemblance to a very small yam, an infant yam, it was called a yam. The confusion has continued to this day. When I hear the sweet potato called a yam, I think about how comforting it must have been for the first African Americans to see a familiar looking food in this unfamiliar land. So while a yam is a yam and a sweet potato is a sweet potato, the two names have been crossed for many, many years!
Here’s a recipe that highlights the sweet potato’s velvety smooth texture. Pair this soup with a crisp green salad and a hunk of sourdough bread for a comforting fall meal.