My wife was given a recipe for Amish sweet bread and for sourdough bread. The starter recipe was seperate and has been lost. It uses dried potatoe flakes. Anyone have a recipe for such?

Boil and mash a medium sized potato.Measure the potato water and add lukewarm water to make 2 cups .Put potato and potato water in a bowl and sprinkle it with 1 package of yeast and 1 Tbsp sugar.Cover loosely and let sit at room temperature at least three days, stirring occasionally.It should have a pungent sour smell.Rifrigerate till ready to use.....Potato or potato water makes an excellent addition to bread.