In a large bowl, dissolve sugar in warm water. Stir in yeast and let sit until foamy (about 10 minutes).

Add salt and oil. Mix in flour one cup at a time until a soft dough forms.

Turn onto a floured surface and knead for 8–10 minutes until smooth and elastic.

Place in a greased bowl, cover, and let rise in a warm spot for 1 hour or until doubled.

Punch down the dough, divide in half, and shape into loaves. Place in two greased 9×5-inch loaf pans.

Cover and let rise again for 30–45 minutes.

Bake at 350°F (175°C) for 30 minutes, until tops are golden and loaves sound hollow when tapped.

Brush with melted butter if desired and cool on wire racks.