In a large bowl, dissolve yeast in 3/4 cup warm water. Add the oil, sugar, molasses, salt and remaining water. Combine flours; add 4-5 cups flour to mixture. Beat until smooth. Add enough remaining flour to form a firm dough.
Turn onto a floured surface; knead until smooth and elastic, 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and let rise in a warm place until doubled, about 1 hour.
Punch dough down. Turn onto a lightly floured surface; divide in half. Shape each portion into a loaf. Place in 2 greased 9x5-in. loaf pans. Cover and let rise until doubled, about 30 minutes.
Bake at 350° until golden brown, 40-45 minutes. Remove from pans to cool on wire racks.