Combine 3 cups flour, undissolved yeast, sugar, salt and baking soda. Heat milk and water until very warm (120º to 130ºF). Add to dry ingredients and beat well. Stir in remaining 3 cups flour to make a stiff batter. Spoon into two 8 1/2 × 4 1/2 × 2 1/2 loaf pans that have been greased and sprinkled with cornmeal. Sprinkle tops with cornmeal.

Cover; let rise in warm place, free from draft, for 45 minutes.

Bake at 400ºF for 25 minutes. Remove from pans and cool on wire rack. To serve, slice and toast.