mashed potato starter

Years ago I had a recipe for potato starter made with mashed potatoes. The unique thing about it was that when preparing the bread, the first rise  was done with a wet dough left overnight in the 'fridge. In the morning , it was ready to knead and place in the pans. Made perfect white bread. I have stopped baking after the kids asked "Why can't we ever have store bought bread?"  Go figure. I have since given the book away. Would deeply appreciate it if someone can help me out.