Most of us don’t know the difference between a yam and a sweet potato. But we do expect one of these tuberous, root vegetables to buddy up with some marshmallows, butter, syrup, and sometimes pecans and make an appearance at our Thanksgiving feast. Where did this interesting tradition come from, and who do we have to thank for it?
First of all, let’s set the record straight about yams and sweet potatoes. They are not the same thing. If we look up genus and species for these two, we find that dioscorea cayenensis is a yam and ipomoea batatas is a sweet potato. They aren’t even related, but we certainly interchange them without batting an eye.
Yams are native to Africa and Asia and are much starchier and drier. They have a cylindrical shape with brown or blackish skin and white, purple, or red flesh. On the other hand, sweet potatoes have an elongated shape with tapered ends. Their skin color ranges from white and yellow to red and brown; and the flesh can be white, yellow, or orange. Sweet potatoes are what we serve at Thanksgiving.
But how did adding marshmallows to sweet potatoes come along? The simple answer: Great Marketing! The Angelus Marshmallow company wanted to influence Americans to use marshmallows as an everyday ingredient. They hired the founder of the Boston Cooking School Magazine of Culinary Science and Domestic Economics to develop recipes using the marshmallow. Shortly thereafter these gooey little wonders started making their annual holiday appearance.