01 - Combine bread flour and water in a large bowl, mixing until just incorporated. Cover the bowl and let the mixture rest for 45 minutes to allow flour hydration.
02 - Add the active sourdough starter and sea salt to the autolysed dough. Mix thoroughly by hand, squeezing and folding until the starter and salt are completely distributed throughout the dough.
03 - Cover the dough and let it rest for 30 minutes at room temperature to relax the gluten network.
04 - Perform 4 sets of stretch and folds at 30-minute intervals. For each set, grab one edge of the dough, stretch it upward, and fold it over the center. Rotate the bowl one-quarter turn and repeat until all sides have been folded.
05 - After completing the final fold, cover the dough and allow it to rise at room temperature for 4-6 hours, or until the dough has approximately doubled in volume and shows visible fermentation bubbles.
06 - Lightly dust your work surface with flour. Turn the dough out gently and shape it into a preliminary round or oval, creating surface tension without deflating the dough.
07 - Place the shaped dough seam side up in a well-floured banneton basket or a bowl lined with a heavily floured kitchen towel. The seam placement will become the aesthetic bottom of your loaf.
08 - Cover and proof for 2-4 hours at room temperature, or refrigerate overnight for 8-12 hours. Cold proofing develops deeper sourdough flavor and makes the dough easier to handle.
09 - Preheat your oven to 450°F with a Dutch oven or heavy lidded pot inside. Allow at least 30 minutes for thorough heating to ensure optimal oven spring and crust development.
10 - Turn the proofed dough onto a piece of parchment paper. Use a bread lame or sharp knife to score the top with a decisive 1/4 to 1/2 inch deep cut. Carefully lift the parchment and dough into the preheated Dutch oven.
11 - Cover the Dutch oven with its lid and bake for 25 minutes. The trapped steam creates the characteristic crispy, blistered crust.
12 - Remove the lid and continue baking for 20 additional minutes, or until the loaf reaches a deep golden-brown color and sounds hollow when tapped on the bottom.
13 - Transfer the baked loaf to a wire rack and allow it to cool completely for at least 1-2 hours before slicing. Cutting while warm will result in a gummy texture.