What ingredient gives potato doughnuts their name?

The ingredient that gives potato doughnuts their name is potato. Recipes typically use mashed potatoes or potato starch in place of some or most of the wheat flour normally used in doughnut dough.

Potato doughnuts are often called Spudnuts. They are generally sweet, fried like other doughnuts, and finished with familiar toppings such as glaze, frosting, or powdered sugar. The potato component can produce a light, fluffy texture, although recipes vary in how much potato they contain.

The idea is older than the modern Spudnut shop. Syndicated potato-doughnut recipes appeared in American newspapers by the 1870s, and a Canadian recipe was printed in the 1915 Five Roses Cook Book. The origin of the food itself is uncertain, so no single inventor is securely established.

A Spudnut should not be confused with a doughnut merely served alongside potatoes. The potato is part of the dough or batter. In some recipes it is prepared mashed potato; in others, potato starch or an instant potato mixture. This ingredient substitution is the defining feature behind the name.