Obtain 1 cup starter (see Ladies of Jubilee). Refrigerate for 3 to 5 days (it won't live past that). Remove from refrigerator and set aside.
Mix: 1 c. warm water 3 tbsp. instant potato flakes
Mix well; add to starter. Let stand out of refrigerator 12 hours, uncovered. Then pour out 1 cup of starter to use to make sour bread. Return rest of starter to the refrigerator for the 3 to 5 days and feed again. (If in the 3 to 5 days you are not ready to bake again, feed starter anyway and throw out 1 cup after it stands the 12 hours.) To make the bread, make a stiff batter in a large bowl of the following: 1 tbsp. salt (or less) 1 c. starter 1/4 c. sugar 1/2 c. corn oil 1 1/2 c. warm water
Grease a large bowl. Add dough and cover lightly with aluminum foil. Leave out overnight. Next morning, punch down and knead on floured surface. Divide into 3 parts and knead each part 8 to 10 times. Place in greased loaf pans. Let rise 4 to 5 hours (no more than 1 inch above top of pans). Bake 30 to 40 minutes on bottom rack. Remove from pans immediately.