Sour Dough Bread

Combine water, starter, the 4 cups of flour, salt and sugar.  Mix well, place in a crock and leave in a warm place for about 18 hours, or until sponge has doubled in size. (If you start at 3 pm you can begin next step at about 9 am the next day). Stir in 1 cup of remaining flour, which has been mixed with the soda: the resulting dough will be very stiff.  Turn dough onto floured surface and knead, adding remaining 1 cup (more or less) as needed.  Knead until smooth- at least 8 minutes, until the dough cannot absorb any more flour.

Shape into 2 oblong loaves or one large Boule.  Place on lighly greased cookie sheet, cover and place in a warm place for 3-4 hours or until nearly doubled in size.  Just before baking brush (I use a spray bottle) with water and make diagonal slashes in the top with a very sharp knife. 

Bake in a hot oven 425 degrees (with a shallow pan of hot water if crispy crust is desired) until crust is medium dark brown. About 45 minutes for oblong loaved 50-55 for boule