Bread Machine Sourdough

Starter (initial batch)
4 cups non-fat milk (or made from dry non-fat milk mix)
2 cups flour
1 tablespoon dry yeast

Mix warm ingredients.
Let stand, covered in a warm place until foamy
Mix again, let stand 2 to 3 days in a warm place
Store in refrigerator until use
Allow to stand until at room temp before use

Bread Recipe
2 cups room temperature starter (about half a batch)
3 cups flour
1 tablespoon sugar
1 teaspoon salt
1-1/2 teaspoon yeast

Bake on 2 lb loaf cycle

The dough ball should pick up more than 3/4 of the dry ingredients at
the end of the mix cycle and all of the dry ingredients before the end
of the first knead cycle.  If there are dry ingredients left at the end
of the first knead cycle, add water a teaspoon at a time until all the
dry stuff is gone.  If the dough is still sticky during the first knead
cycle, add flour a tablespoon at a time until the dough ball is not
sticky.

At end of last rise (2nd set of bread machine beeps) remove dough and paddle
hand knead dough on a lightly floured surface to beat down
return to bread machine for the rest of the bake cycle

Replenish starter (if there isn't 4 cups worth)
Add 2 cups non-fat milk
Add 1 cup flour
Stir
Let stand in a warm place for 2 days
Store in refrigerator