Mix the starter and water: In a large glass bowl, add the sourdough starter. Pour in the warm water and mix until the starter is fully dissolved.
Incorporate the flour: Add the bread flour and mix until no dry bits remain. The dough will be shaggy. Cover and let it rest for 30 minutes.
Add salt: Sprinkle the salt over the dough. Use wet fingers to press it in, then shape the dough into a rough ball.
Stretch and fold: Cover the bowl and let the dough rest for 45 minutes. Perform a set of stretch and folds: grab one side of the dough, stretch it upward, and fold it over. Rotate the bowl and repeat three times in total. Cover and let rest.
Repeat stretch and folds: After 45 minutes, perform another round of stretch and folds. Cover and rest.
Coil fold the dough: Gently lift the dough from the center with both hands, allowing it to fold under itself. Repeat two more times for a total of three coil folds. Let the dough rest for 30 minutes, then perform one more round of coil folds.
Bulk fermentation: Let the dough rise, covered, in a warm room until it doubles in size. It should spring back slightly when pressed.
Shape the dough: Transfer the dough onto a lightly floured surface and gently stretch it into a square. Fold the right and left sides inward, overlapping each other. Roll the dough tightly into a burrito shape.
Proof in a banneton: Dust a banneton basket with flour and place the dough inside, smooth side down. Cover and refrigerate for 12 hours.
Preheat the oven: Set the oven to 450°F (232°C). You can preheat a Dutch oven inside, but for this recipe, it’s not required.
Score the dough: Flip the dough onto a piece of parchment paper. Use a sharp blade to score the dough, ensuring at least one deep score for proper expansion.
Bake: Place the loaf into a Dutch oven with the parchment paper. Cover with the lid and bake for 20 minutes.
Finish baking: Remove the lid and bake for another 15-20 minutes, or until the loaf is golden brown.
Cool completely: Let the bread cool on a wire rack before slicing.