Combine yeast and 1/4 cup warm water in a 2-cup glass measuring cup; stir in remaining 1 3/4 cups warm water, and let mixture stand 5 minutes.
Combine 4 cups flour and sugar in a large bowl. Stir in yeast mixture and oil.
Cover dough, and let rise in a warm place (85°), free from drafts, 30 minutes.
Add salt and enough remaining flour to make a stiff dough, beating at medium speed with a heavy-duty electric mixer 6 to 8 minutes. Cover and let rise in a warm place, free from drafts, 1 hour or until doubled in bulk.
Divide bread dough in half, and shape each portion into a 12-inch loaf. Place each loaf on a lightly greased baking sheet sprinkled evenly with 2 tablespoons cornmeal. Cover loaves, and let rise in a warm place, free from drafts, 30 minutes or until doubled in bulk.
Bake at 425° for 15 minutes. Stir together egg white and 2 tablespoons water. Brush over loaves, and bake 5 to 10 more minutes or until loaves sound hollow when tapped.