In a large mixing bowl, combine the sourdough starter and warm water. Stir until the starter is dissolved.
Add the bread flour and salt to the mixture. Mix together until a rough dough forms.
Cover the bowl with a towel and let the dough rest for 30 minutes.
Perform the first set of stretches and folds by grabbing the edge of the dough, stretching it upward and folding it over the center. Rotate the bowl and repeat 3 more times.
Repeat the stretches and folds every 30 minutes for a total of 4 sets.
After the last fold, cover the dough and let it bulk ferment at room temperature until it has increased in volume by about 50%, approximately 4 to 6 hours depending on starter activity and room temperature.
Transfer the dough onto a lightly floured surface and pre-shape it into a round. Let it rest for 20-30 minutes.
Perform the final shaping into a round boule or batard shape.
Place the shaped dough seam-side up in a well-floured flour sack towel-lined proofing basket or bowl.
Cover and refrigerate the dough overnight (8-12 hours) for the final proof.
Preheat your oven to 450°F (230°C) with a Dutch oven inside for at least 30 minutes.
Carefully remove the hot Dutch oven, invert the dough onto parchment paper, and score the top with a sharp blade.
Place the dough with the parchment into the Dutch oven, cover with the lid, and bake for 20 minutes.
Remove the lid and bake for an additional 20-25 minutes until the crust is golden and crisp.
Remove the bread from the oven and cool on a wire rack for at least 1 hour before slicing.