Is it a Yam or a Sweet Potato? Phew, that is one contentious question! You should see my family get into it. In the East we call them Sweet Potatoes, in the West they're known as Yams.
Yams, Sweet Potatoes, and Potatoes have a tangled history. All three are quite distinct. I would bet that if you've eaten "Yams" in North America, they were actually Sweet Potatoes. And since we're on this topic we must include Potatoes in the conversation. Though not often confused with the other two roots, Potatoes, have come along for this wild etymological ride. It was the Sweet Potato that lent its name to the Potato – not the other way around.
Now, how did the names get so messed up? Let’s start with the Batatas. Sound familiar? It’s 1492. Christopher Columbus bumps into the Carribean. While harassing the indigenous population, his crew encounters a Starchy Root vegetable. The local Taino call it the Batatas and it’s now what we know as the Sweet Potato. The Sweet Potato, along with Columbus, has been part of American culture from day one. Sweet Potatoes are a staple dish at Thanksgiving and are very popular in the Southern States. It’s North Carolina’s State Vegetable.
Potatoes, Patatas, Batatas…The Spanish word for Potato is Patata, which by no leap of the imagination clearly came from Batatas. While the Spanish were crusading through South America in the 1500’s, they came across another Starchy Root called the Papa. What we now call the Potato. The Potato, though initially mistrusted in Europe, went on to become a staple crop. High yielding, cold hardy, and easy to store – it was an ideal crop for Europe peasants, though criticized as a dirty food by upper class Britons. It led to huge population growth, though over-reliance combined with an outbreak of Late Blight lead to the devastating Irish Potato Famine (and why many of our ancestors are here in North America).
The Yam has it’s own long history and was only tangled up with Sweet Potatoes through in the last couple centuries. The Yam is a tropical grass that originates from West Africa (important food in Nigeria). It’s English name likely came from various West African words including Nyami and Iyan. It’s also widely eaten in East Asia and the Caribbean. There are many varieties, both wild and cultivated. Rough skinned tubers can range from potato size to several feet long. Its flesh can be a variety of colours (just like Sweet Potatoes and Potatoes). The Yam was brought to the Caribbean during the slave trade and is still grown there. Similarity between white Sweet Potato and the white Yam seems to have led to the names crossing over in the Southern US.
Rebranding the Sweet Potato
In the mid 1900’s, Sweet Potato farmers in the United States started growing a softer, orange variety of sweet potato. The one that we eat today. The industry wanted to differentiate their new crop from the firm, white Sweet Potato that Americans were accustomed to. Up to that point, Sweet Potatoes and Potatoes were both generally white fleshed. The word Sweet Potato, after all doesn't sound terribly exciting or or healthy ("Sweet + Potato"?? Come on). I would love to have heard the rationale for choosing Yam as the new name. From what I have read, the word Yam (but not the food itself) had been floating around the Southern US since the time of Slavery as an alternative to the white fleshed Sweet Potato.
This recent re-branding of the Sweet Potato to “Yam” has lead to a lot of this confusion. In the USA producers are required to label Yams as Sweet Potatoes. It’s fair to differentiate the orange "Yam" from the white Sweet Potato. "Yams" become soft when cooked (masheable) whereas the older white varieties stayed firm. To add to the confusion, in Eastern Canada they don’t often use the term Yam, they are just orange Sweet Potatoes.
Sweet Potatoes (Ipomoea batatas) have tapered ends.
Originated in Central America. It’s North Carolina’s State Vegetable.
Orange varieties known as Yams in North America.
Related to the Morning Glory Flower.
Yams (Genus Discorea various species) are chunky or tapered.
Originated in Tropical West Africa. Important crop in West African, East Asia, and Caribbean. Still a specialty item in North America.
Related to grasses and lilies.
I've never seen one in my life!
Potatoes (Solanum tuberosum) are round or egg shaped.
Orginated in South American Andes. Thousands of varieties.
Nightshade Family with Tomatoes, Peppers, Eggplants, Tomatillos, Husk Cherries.
Graham Waugh, Human Nature, Calgary, New Brunswick, Food Writer, Farm, Salad Spinners