Back in the 1930s, potatoes were cheaper than flour. Grandma was looking for ways to stretch her dollar, and started adding mashed potatoes to doughnuts. We replace about 1/3 of the flour in our recipe with fresh riced mashed potatoes. It gives them a unique texture and a longer shelf life than your average doughnut. They don’t taste like potatoes; they taste like a really good doughnut.