Whether we like it or not and whether we eat them or not, there are some foods that make Thanksgiving, well, Thanksgiving. The meal just wouldn’t look the same without turkey, stuffing/dressing, jellied cranberries, pumpkin pie, green bean casserole, and sweet potatoes….or are those yams? No matter if we roast them, mash them, make them into a pie, or top them with marshmallows, virtually no other Turkey Day food causes as much confusion. So, once and for all, let’s take a look at yams and sweet potatoes, and see how this bright orange tuber made it onto our holiday table.
First, let’s tackle the name issue. What we eat are not really yams: yams are dry, starchy, can grow up to 5 feet long, come from the Dioscoreaceae family, and are native to Africa and Asia; their name originates from the Spanish/Portuguese interpretation of West African languages which used the term to identify eating, the Fulani term nyami, as well as the yam itself, the Twi anyinam. Truthfully, we are eating sweet potatoes, which are native to Central and South America, come from the Convolvulaceae family, and are smaller and sweeter than yams: their name comes from the Spanish writing (patata) of a Hispaniola Taino word for the sweet potato, batata.
The first definitive usage of the term yam can be found in an undated piece of sheet music circa 1775 by Charles and Samuel Thompson of London, found in Notes & Queries, which, discussing “the Negroes farewell to America”, lyricises “Farewell all de yams, and farewell de salt fish.” Conversely, the first mention of the sweet potato can be found in a 1597 work by John Gerard, entitled The Herball Or General History of Plants, where he writes that: “Of Potatoes… This plant..is generally of us called Potatus or Potatoes. It hath long rough flexible branches trailing upon the ground, like unto Pompions… Clusius calleth it Battata, Camotes, Amotes, and Ignanes: in English Potatoes, Potatus, and Potades.”
So, if the term sweet potatoes was used almost 200 years before the term yams and sweet potatoes were even eaten by Christopher Columbus’ crew during his expeditions, why do we still call sweet potatoes yams? Well, we don’t really know. There’s a theory that African slaves in the U.S. South began calling sweet potatoes (which were easy to grow in the South) yams due to their slight similarity to African true yams, but that’s never been totally proven. Additionally, in the 1930s, the horticulture department at Louisiana State University developed a more moist and fluffy type of sweet potato, which, marketed as a “Louisiana yam” to differentiate it from other sweet potatoes, soon became the premier variety of sweet potato to grow and eat.
While Native Americans were baking sweet potatoes long before the English colonists began following their example, what really made sweet potatoes a Thanksgiving staple was – believe it or not – marshmallow advertising. Along with a renewed interest in the “traditional Thanksgiving foods” during the early 1900s, sweet potatoes became a staple thanks to the founder of Boston Cooking School Magazine, Janet McKenzie Hill, who was hired by Angelus Marshmallows in 1917 to create recipes utilising the fluffy sweet in everyday recipes. Distributed in a number of their recipe booklets, the idea of sweet potatoes topped with the sweetness and texture of marshmallow, was a success with American households that soon became a part of traditional Thanksgiving table.