In a large mixing bowl, combine the bread flour and water. Mix thoroughly until no dry flour remains. Cover the bowl with a clean kitchen towel or plastic wrap and let it rest at room temperature for 1 hour.
Add the active sourdough starter and salt to the dough. Mix well using your hands or a spoon until fully incorporated. Cover the bowl again and let the dough rest at room temperature for 30 minutes.
Perform a series of stretch and folds every 30 minutes for the next 2 hours: reach under the dough, stretch it upwards, and fold it over itself. Repeat this 4 times per session. After the final stretch and fold, cover the dough and let it ferment at room temperature for 12 to 16 hours, until it has doubled in size and is bubbly.
Generously flour a work surface and gently turn the dough out onto it. Shape the dough into a round loaf by folding the edges toward the center. Place the dough seam-side down on a piece of parchment paper. Cover with a kitchen towel and let it rest for 1 to 2 hours until it has risen noticeably.
About 30 minutes before baking, place a Dutch oven with its lid inside your oven and preheat to 450°F (230°C).
Carefully remove the hot Dutch oven from the oven. Using the parchment paper, lift the dough and place it into the Dutch oven. Score the top of the dough with a sharp knife or razor blade to allow for expansion.
Cover with the lid and bake for 30 minutes. Remove the lid and bake for an additional 15 minutes until the crust is deep golden brown and crisp.
Remove the bread from the Dutch oven and transfer it to a wire rack. Let it cool completely, about 1 to 2 hours, before slicing.