Mix yeast and water in a a large mixing bowl or stand mixer. Let sit until dissolved (10 minutes).
Add sugar, salt, oil and flour (two cups a time). Mix (with wooden spoon or dough hook if using a stand mixer) until it comes together in a large dough ball.
Adding a little flour to the top of the dough or on your hands so it doesn't stick to your hands, remove dough from bowl.
Coat bowl with a thin layer of oil.
Form dough into a nice, round ball and place in greased bowl.
Cover bowl with a towel and place in a warm spot.
Let rise for one hour.
Punch down risen dough (putting a little more flour on your knuckles if needed not to stick).
Remove and stretch dough slightly, then form back into a ball and return to bowl.
Cover and let rise for another hour.
Preheat oven to 350F and grease two loaf pans.
Split dough into two equal portions.
Form into smooth loaves and place in prepared pans.
Let rise and rest for at least 10 minutes before baking.
Bake for 30 minutes on center rack.
Melt butter in microwave.
Pop baked loaves out right away and place on wire rack.
Brush top with melted butter.
Place towel over loaves while they cool before slicing.