SOURDOUGH: Prepare the sourdough and ripen for 14 to 16 hours at 70°F.
MIXING: Add all the ingredients except the walnuts to the mixing bowl. In a spiral mixer, mix for 3 minutes on first speed, and 3 to 4 minutes on second. A moderate gluten development should be noted. Add the walnuts and mix on first speed just until they are uniformly disperse