In a large mixing bowl, combine the bread flour and water. Mix until no dry flour remains. Cover and let rest for 1 hour (autolyse).
17.5 oz bread flour, 12.5 oz water
Add the sourdough starter and salt to the dough. Mix thoroughly using the stretch and fold method.
3.5 oz active sourdough starter, 0.35 oz salt
Cover the dough and let it ferment at room temperature for 6-8 hours, performing stretch and folds every 30 minutes for the first 2 hours.
Shape the dough into a round or oval loaf. Place it in a proofing basket or bowl lined with a floured kitchen towel. Cover and let it rise for 2-4 hours, or until doubled in size.
Preheat the oven to 450°F (230°C) with a Dutch oven inside. Once preheated, carefully transfer the dough into the Dutch oven, score the top, and cover with the lid.
Bake for 20 minutes with the lid on, then remove the lid and bake for another 25 minutes or until the crust is deeply golden.
Let cool on a wire rack before slicing.
Notes
The dough can also be proofed overnight in the refrigerator for a more developed flavor.
Adjust water content based on humidity and flour type.