In a medium saucepan, heat the water with 3/4 cup of the milk just until lukewarm. Add the cornmeal and cook over low heat, stirring constantly, just until small bubbles appear around the edge. Remove from the heat. Stir in the butter, molasses and salt; transfer to a large bowl and let cool.
Meanwhile, in a small saucepan, heat the remaining 1/4 cup of milk with the sugar until lukewarm. Remove from the heat. Sprinkle the yeast over the milk and let stand until foamy, about 10 minutes. Stir the yeast mixture into the cornmeal. Stir in 6 1/2 cups of the flour, until a stiff dough forms.
Turn the dough out onto a lightly floured surface and knead until smooth and elastic, adding the remaining 1/2 cup of flour as needed. Form the dough into a ball and transfer it to a lightly buttered bowl. Cover the bowl with plastic wrap and let rise in a warm, draft-free spot until doubled in bulk, about 1 hour.
Lightly butter two 8 1/2-by-4 1/2-inch loaf pans. Punch down the dough and divide it in half. Form each half into a loaf and place in the prepared pans. Dust the tops lightly with flour, cover with a clean, dry kitchen towel and let rise in a warm, draft-free spot until nearly doubled in bulk, about 1 hour.
Preheat the oven to 350°. Bake the loaves for 50 minutes, or until the tops are brown; carefully turn out onto a rack. The loaves should sound hollow when tapped on the bottom; if they don't, return to the pans and bake a few minutes more. Cool completely before slicing.
The bread can be stored at room temperature for up to 4 days.