Sourdough cooking uses a "starter" which is simply flour and water with a yeast strain growing in the mix. You keep adding new flour and water to this, using some of the mix in your cooking and keeping some back as new starter. Nothing but flour and water will go into the starter.

Keep one cup of batter in a jar in the refrigerator as a starter. Use it at least once every six months and it will remain good. When not used for a while some liquid will form on the top of the batter and may become a bit dark. As long as it does not mold it is fine. The day before you want to do your sourdough cooking you need to make some "basic batter".  This simply involves removing your cup of starter from the refrigerator and adding two and one half cups of flour and two cups of water. Mix this in a glass bowl, cover and let sit overnight. The next day remove one cup of batter and store in a glass jar in the refrigerator. This will be the starter that allows you to continue the process of sourdough cooking. The remainder is the "basic batter" used in the following recipes.

Sourdough Bread
2 cups milk 1/4 cup wheat germ
2 tbspn butter 2 cups wheat flour
2 tspn salt 4 cups white flour
2 tbspn sugar 1 pkg active dry yeast
1/4 cup honey 2 tspn baking soda

Scald two cups of milk and melt butter and honey in milk. Allow to cool to lukewarm, mix yeast in milk and stir to dissolve. Add to the basic batter. Sift into dough two cups of wheat flour and wheat germ. Blend sugar, salt and soda until smooth and sprinkle over top of dough, stirring in gently. Set dough in warm spot, cover with cloth and let set for 30 minutes.

Break down and sift in remaining flour until the dough is too stiff to stir with a spoon. Turn out on floured board and begin to knead with hands. Work in remaining flour, kneading with heels of hand 100 times until the dough is light and satiny to the touch. Note: Quantity of flour will vary - better too little than too much.

Let rise in a greased bowl. Punch down, divide into three equal portions, and place in greased bread pans. Let rise. Bake 20 minutes  at 400 degrees with pans covered with aluminum foil. Reduce temperature to 325 and remove foil. Bake until done - about another 20 minutes.

Sourdough Waffles
1 egg
4 tablespoons cooking oil
1/4 cup instant or evaporated milk
Mix the above into bowl of basic batter. In a small bowl combine the following:
1 teaspoon salt
1 teaspoon soda
2 tablespoons white sugar
Sprinkle the mixture of salt, soda, and sugar over the batter and fold in gently. Let rest 5 minutes while the waffle iron heats. Cook at a slightly hotter iron that you would normally use. I oil the iron before each waffle and cook 4 minutes.

For pancakes use the waffle batter with two tablespoons oil instead of 4 tablespoons oil.

Link to photos of the Sourdough Jack recipe page that came with starter here.