In a small bowl, dissolve yeast and sugar in warm water. Let stand until creamy, about 10 minutes.
In a large bowl, combine the yeast mixture with warm milk, 3 cups flour, salt and baking soda; stir well to combine. Stir in the remaining flour, 1 cup at a time until a stiff batter is formed. Spoon batter into two lightly greased 9x5 inch loaf pans that have each been sprinkled with 1 tablespoon cornmeal. Cover and let rise in a warm place until doubled in size, about 45 minutes.
Preheat an oven to 400 degrees F (200 degrees C).
Bake in preheated oven for about 25 to 30 minutes or until the top is golden brown and the bottom of the loaf sounds hollow when tapped. Remove from pans immediately and place on wire racks to cool.