01 - Dissolve sugar in warm water in a large bowl. Sprinkle yeast over water and let stand 5 to 10 minutes until foamy.
02 - Stir salt and oil into yeast mixture. Gradually add flour, 1 cup at a time, mixing until soft dough forms that pulls away from bowl sides.
03 - Knead dough on lightly floured surface for 6 to 8 minutes until smooth and elastic.
04 - Place dough in lightly greased bowl. Cover and let rise in warm place until doubled, about 1 hour.
05 - Punch down dough and divide in half. Shape each half into loaf and place in two greased 9x5-inch loaf pans.
06 - Cover pans and let rise until dough is about 1 inch above rim, about 30 to 45 minutes.
07 - Preheat oven to 350°F.
08 - Bake loaves for 25 to 30 minutes until golden brown and sound hollow when tapped.
09 - Brush tops with melted butter if desired. Remove from pans and cool on wire rack before slicing.