1. Activate Your Starter and Mix the Dough: The night before or early in the morning, ensure your sourdough starter is active and bubbly. In a large bowl, combine the active sourdough starter with the warm water. Stir until the starter is mostly dissolved. Add the bread flour and salt to the bowl. Mix with a wooden spoon or your hands until no dry flour remains and a shaggy dough forms. Cover the bowl with a damp cloth or plastic wrap and let it rest for 30 minutes. This resting period, called autolyse, allows the flour to fully hydrate.

2. Perform the First Stretch and Fold: After the autolyse, wet your hands slightly. Grab a portion of the dough from one side, gently stretch it upwards, and fold it over to the opposite side of the bowl. Rotate the bowl a quarter turn and repeat this process three more times, completing one full set of stretch and folds. This helps develop gluten. Cover the bowl again.

3. Continue Developing the Dough with More Folds: Repeat the stretch and fold process three more times, performing a set every 30 minutes for the next 1.5 hours. After the fourth set, the dough should feel more elastic and cohesive. Cover the bowl and let the dough rest at room temperature for 4-6 hours, or until it has visibly increased in size by about 30-50% and looks bubbly. This is the bulk fermentation stage. Alternatively, you can place it in the refrigerator for 12-18 hours for a slower, colder bulk fermentation, which often develops more flavor.

4. Shape Your Loaf: Gently turn the dough out onto a lightly floured surface. Avoid deflating it too much. Shape the dough into a round or oval loaf. For a round loaf, gently pull the edges of the dough towards the center, creating tension on the surface. For an oval, gently roll and tuck the dough to form an elongated shape. The goal is to create a taut surface.

5. Prepare for Final Proofing: Lightly flour a proofing basket (banneton) or a bowl lined with a floured kitchen towel. Carefully transfer the shaped dough, seam-side up, into the prepared basket. Cover the basket with a plastic bag or plastic wrap to prevent drying.

6. Final Proof and Preheat Your Oven: Allow the dough to proof at room temperature for 1-3 hours, or until it feels puffy and springs back slowly when gently poked. For a deeper flavor and easier handling, you can also cold proof the dough in the refrigerator for 8-12 hours (or overnight). About 45 minutes before baking, place a Dutch oven with its lid into your oven and preheat to 450 F (230 C).

7. Score and Bake Your Sourdough: Carefully remove the hot Dutch oven from the oven. Gently invert the dough from the proofing basket into the hot Dutch oven. Using a sharp knife or a bread lame, score the top of the dough with a design of your choice (a simple cross or a single slash works well). This allows the bread to expand properly. Cover the Dutch oven with its lid and bake for 30 minutes.

8. Finish Baking and Cool: After 30 minutes, remove the lid from the Dutch oven. Reduce the oven temperature to 400 F (200 C) and continue baking for another 10-15 minutes, or until the crust is deeply golden brown and the internal temperature reaches 200-210 F (93-99 C). Carefully remove the bread from the Dutch oven and transfer it to a wire rack to cool completely before slicing. This is crucial for the crumb to set properly.