In a large mixing bowl, combine the sourdough starter, lukewarm water, and 3 cups of bread flour. Mix until a shaggy dough forms.
Add the salt and gradually incorporate the remaining flour until a sticky dough forms.
Knead the dough on a floured surface for about 10 minutes or until it becomes smooth and elastic.
Place the dough in a lightly oiled bowl, cover with a cloth, and let it rise at room temperature for 4-6 hours, or until it doubles in size.
Preheat your oven to 450�F (230�C). If you have a Dutch oven, preheat it as well.
Shape the dough into a round loaf and place it in a floured banneton or on parchment paper.
Let the dough rise for another 30-60 minutes.
Score the top of the dough with a sharp knife or lame.
If using a Dutch oven, transfer the dough into the preheated pot. Otherwise, place the parchment paper with the dough on a baking stone or tray.
Bake for 25-30 minutes with the lid on (if using a Dutch oven), then remove the lid and bake for an additional 10-15 minutes or until the crust is golden brown.
Allow the bread to cool on a wire rack before slicing.