Place 1/2 cup water and cornmeal in a small saucepan. Bring to a boil over medium heat, stirring occasionally. Cook until mixture thickens; about 5 minutes. Remove from heat and stir in the butter or margarine and molasses. Let cool to lukewarm.
In a small mixing bowl, dissolve yeast in 1/2 cup warm water. Let sit until creamy; about 10 minutes.
In a large mixing bowl, combine the cooled cornmeal mixture with the yeast mixture; stir until well blended. Add 2 cups of the flour and the salt; mix well. Add the remaining flour, 1/2 cup at a time, stirring well after each addition. When the dough has pulled together, turn it out onto a lightly floured surface and knead until smooth and elastic, about 8 minutes.
Lightly oil a large mixing bowl, place the dough in the bowl and turn to coat with oil. Cover with a damp cloth and put in a warm place to rise until doubled in volume, about 1 hour.
Preheat oven to 200C/390F.
Deflate the dough and turn it out onto a lightly floured surface and form into a loaf. Place the loaf in a lightly greased 9 x 5 inch (23 x 13 centimeter) loaf pan. Cover with a damp cloth and let rise until doubled in volume, about 40 minutes.
Bake at 200C/390F for about 30 minutes or until the top is golden brown and the bottom of the loaf sounds hollow when tapped.
Makes 1 loaf.