Combine 1⅓ cups flour and the yeast with 3/4 cups warm water until you have a thick batter. Mix well for two minutes or so. Let rest overnight, or at least 5 hours.
Add the remaining 2⅔ cups of flour, the salt, butter, and 3/4 cups water. Mix well until you have a soft dough.Let rest 1 hour. Roll dough into 2 baguettes (or one long one if you have a large enough baking pan. Place on baking pan and let rest 1 hour.
Preheat oven to 425° F. Before putting in the oven, slash with lame in a diagonal across each loaf. Brush with water for a crispier crust. Bake 25-30 minutes. Cool on a rack.