Potato flour is used by professional bakers to improve breads and pastries by making them moister and retarding staling. Potato flour is hygroscopic, that is, it attracts moisture rather than drying out and keeps your breads moister longer. Add it to your flour when mixing, about one tablespoon per loaf. More can be added for flavor if you prefer. Potato flour has a slight, almost sourdough-like flavor in greater concentrations.