Mix starter and water to loosen. Add flour and mix until well combined. Leave out on on the counter over night (at least 12 hours), covered with plastic wrap and then a dish towel.
Making Bread Dough
Mix sponge and 1 1/4 cup of water in the bowl of an electric mixer until smooth.
Next, add 5 cups of flour and 1 teaspoon of salt. Mix well either by hand or with an electric mixer. If using a mixer, mix on low for 5-10 minutes.
Place dough into a buttered bowl, cover with plastic wrap and a towel, let rise for 6-10 hours or until size has doubled.
Remove dough from bowl, form into the shape loaf you want, and place it for second rise in whatever dish you will bake in. Cover with just a towel this time. Let rise for 2 hours.
Pre-heat oven to 425°. Slash top of bread in whatever pattern you choose, 1/4″ deep, with a sharp knife.
Bake at 425° for 40 minutes, rotating bread 180 degrees halfway through baking. For a softer loaf, bake for 10 minutes at 425° and 40 minutes at 375°.