In a large bowl, combine warm water, yeast, salt, oil, sugar, and 4 cups flour. Mix thoroughly, and let sponge rise until doubled in size.
Gradually add about 4 cups flour, kneading until smooth. Place dough in a greased bowl, and turn several times to coat. Cover with a damp cloth. Allow to rise until doubled.
Punch down the dough, let it rest a few minutes. Divide dough into three equal parts. Shape into loaves, and place in three 8 1/2 x 4 1/2 inch greased bread pans. Let rise until almost doubled.
Bake at 350 degrees F (175 degrees C) for 35 to 45 minutes. The loaves may need to be covered for the last few minutes with foil to prevent excess browning.
