The Sticky History Of Topping Sweet Potato Casserole With Marshmallow
Today, sweet potatoes and marshmallows are an unquestionable combination, but they weren't always an iconic pairing. After all, this holiday dessert requires a serious sweet tooth but sugary marshmallows topping caramelized sweet potatoes aren't for everyone. So, where did this Thanksgiving classic come from? Well, there is evidence of earlier sweet potato casseroles that leave out the sticky white fluff we cover them in today.
Looking at the history of sweet potatoes, we found that it wasn't even until the 1740s that Americans began to call them "sweet potatoes" to distinguish them from regular potatoes. Initially, sweet potatoes were roasted in savory herbs and seasonings, such as salt, vinegar, and wine, according to the Library of Congress. Candied sweet potatoes, or yams, came much later; the earliest written recipe for this sweet casserole is from 1796, found in American Cookery by Amelia Simmons.
Simmons's recipe was titled "potatoe pudding," but historians suspect that the potatoes she used were, in fact, sweet potatoes (via Four Pounds Flour). Her "potatoe pudding" is quite similar to the sweet potato casseroles we prepare today: The sweet potatoes are boiled and macerated with butter, sugar, and milk. Then, they are topped with tons of eggs, which seem to be whipped into a sugary meringue.
A marketing scheme
So when did marshmallows enter the picture? Well, Atlas Obscura writes that a century after the publication of Simmons' cookbook, these confectionery treats became much more accessible to the public thanks to Joseph Demerath, who decided to use gelatin rather than mallow plant (which made it very expensive). With the democratization of marshmallows, they began to be used on festive occasions — Thanksgiving in particular. At first, these treats were quite alluring on their own, left in baskets at the center of the table for everyone to indulge in. Eventually, though, they were used as ingredients in other dishes, and marshmallow producers caught onto these cooking trends.
Alongside the marshmallow baskets came sweet potato desserts, which were becoming increasingly popular, as Saveur points to in multiple cookbook recipes. Eventually, both sweets converged in 1917, when the marketers of Angelus Marshmallows hired Boston Cooking School Magazine's founder, Janet McKenzie Hill, to create marshmallow recipes. Hill combined the tuber with the sweet, fluffy confectionery, writing the first modern sweet potato casserole recipe, per Library of Congress. Although this combination was initially met with some resistance from Southerners, it stuck around out of the many forgotten inventive marshmallow recipes, like this classic Watergate salad.