This bread, with its deep brown crust, rich, deep, flavor, and mild tang relies on ripe, active starter for its rise. Without the addition of commercial yeast, its a true sourdough purist's loaf. Are you a beginning sourdough baker? Please start with our rustic sourdough bread recipe, which offers the added security of commercial yeast. Once you master that, move on to this loaf, which is more appropriate for intermediate sourdough bakers.