1. 1. Combine Wet Ingredients and Starter: In a large mixing bowl, gently whisk together the active sourdough starter, warm water, and sugar until well combined. The mixture should look milky and slightly bubbly from the active starter.

2. 2. Add Dry Ingredients: Add the salt and flour to the wet mixture. Using a wooden spoon or a sturdy spatula, mix until all the flour is incorporated and no dry streaks remain. The dough will be shaggy and sticky – resist the urge to overmix or knead.

3. 3. First Proof (Bulk Fermentation): Cover the bowl tightly with plastic wrap or a damp kitchen towel. Let the dough rest at room temperature (around 70-75F / 21-24C) for 8-12 hours, or until it has noticeably increased in volume (about doubled) and shows signs of activity like small bubbles on the surface. This long proof develops flavor.

4. 4. Shape the Dough: Lightly flour your work surface. Gently scrape the dough out of the bowl onto the floured surface. Fold the edges of the dough towards the center to form a rough ball. Avoid deflating it too much. Place the dough seam-side up into a floured proofing basket (banneton) or a bowl lined with a floured kitchen towel.

5. 5. Second Proof (Final Rise): Cover the proofing basket/bowl and let it rise for another 2-4 hours at room temperature, or until it feels light and airy. Alternatively, you can cold proof it in the refrigerator for 12-24 hours for a deeper flavor development.

6. 6. Preheat Oven and Dutch Oven: About 30 minutes before baking, place your Dutch oven with its lid into the cold oven. Preheat the oven to 450F (232C). This ensures the Dutch oven is scorching hot, which is crucial for the crust.

7. 7. Bake the Loaf: Carefully remove the hot Dutch oven from the oven. Gently invert the dough from the proofing basket into the hot Dutch oven. You can score the top of the dough with a sharp knife or razor blade if desired (a simple “X” or a single slash works well). Cover the Dutch oven with its lid and bake for 30 minutes.

8. 8. Finish Baking for Crispness: Remove the lid from the Dutch oven. Reduce the oven temperature to 400F (200C) and continue baking for another 15-20 minutes, or until the crust is deeply golden brown and sounds hollow when tapped on the bottom.

9. 9. Cool Completely: Carefully remove the bread from the Dutch oven and place it on a wire rack to cool completely before slicing. This is critical for the texture and flavor to fully develop.