Feed your starter at night before you go to bed*. In the morning, mix the first 3 ingredients in a large bowl.
Add the flour and mix until a shaggy dough is formed. Form the dough into a ball in the bowl.
Cover the dough with a lid and let sit for 6-12 hours (depending on the temperature of the room, warmer temperature will result in a quicker rise).
Once the dough has risen (doubled) and is bubbly, turn it out onto a lightly floured counter. Stretch the dough into a loose rectangle. Fold it into thirds (like folding a piece of paper into thirds). Pull the corners in and form a ball. Flip it over so the smooth side is on top. Using your hands, gently pull the ball towards you several times. Place dough on a piece of parchment paper and put the empty bowl over the dough ball, as a cover.
Place Dutch oven in the oven and preheat to 450°, as the dough rests on the counter. Let the dough rest for about 30 minutes.
Take the bowl off the dough and using a sharp knife or lame, score the dough. Remove the Dutch oven and place the parchment paper and dough into the Dutch oven. Put the lid back on and put Dutch oven in the oven.
Reduce the oven temperature to 400° and bake for 40 minutes. Remove the lid during the last 10-15 minutes of baking. Leave the lid on longer for softer crust and take the lid off sooner for a crispier crust. The internal temperature of the bread should be 200°.