Place the yeast, sugar and warm water in a mixing bowl. Stir and let stand for about 10 minutes, until creamy and foamy. Add the melted butter and eggs and mix well.Combine the flour with the salt. Add it to the yeast mixture, 1 or 2 cups at a time, until it forms a soft dough. Place the dough on a well-floured board and knead until the dough becomes smooth and elastic, about 5 minutes. Place the dough in a large, well-greased bowl, then flip the dough over to coat with oil. Cover with plastic wrap or a towel and let stand in a warm place for about 1 hour, or until doubled in size.
Preheat the oven to 375 degrees. Punch the dough down, form it into a loaf and place in a greased loaf pan. Bake for about 1 hour, or until the bread is golden brown and sounds hollow when tapped. Let cool before slicing.