Boudin is San Francisco's oldest continuously operating business, since 1849, and is the home of The Original San Francisco Sourdough. Today, they still bake their sourdough fresh every day using the same mother dough cultivated from a gold miners sourdough starter. Brown 'N Serve Directions: Thaw the loaf. Lightly mist the loaf with water. Heat @ 400 degrees for 8-10 minutes.