-- Sourdough Starter -- In a large bowl or crock mix together the flour, water and sugar. Cover and let mixture stand in a warm place for 2-3 days or until fermented. (Yields about 1? cups.)

-- For the bread --

1. Sprinkle the yeast into the warm water and let stand for 2 minutes. Stir to dissolve.

2. Transfer the yeasr to a large mixing bowl. Stir in the sourdough starter, 4 cups of flour, salt and sugar. Stir rapidly for 3 minutes. Transfer to a large oiled bowl, cover with a cloth and let rise in a warm place until doubled in size, about 2 hours.

3. Combine the baking soda with 1 cup flour and add it to the dough. Stir well.

4. Turn the dough onto a lightly floured surface and knead in the remaining 1 cup of flour. More may be needed. Knead until the dough is smooth and not sticky. Shape the dough into 1 large round loaf and place it on a buttered baking sheet. Cover the dough and let rise a second time until almost doubled in bulk, about 1 hour.

5. Preheat the oven to 400F.

6. Brush the top of the loaf with water and slash the top diagonally with a sharp knife. Place a shallow pan of hot water in the bottom of the oven. Bake the bread for 45 to 50 minutes or until golden. Remove from oven and cool before slicing.