01 - Combine bread flour and room temperature water in a large mixing bowl. Mix until just incorporated with no dry patches remaining. Cover the bowl and let rest at room temperature for 1 hour to allow flour hydration.
02 - Add active sourdough starter and fine sea salt to the autolysed dough. Mix thoroughly by hand or with a dough scraper until the starter is fully distributed and the dough becomes cohesive and smooth.
03 - Complete 4 sets of stretch and fold technique at 30-minute intervals over 2 hours. For each set, grab one edge of the dough, stretch it upward, and fold it over the center. Rotate the bowl and repeat for all four sides. Keep the dough covered between sets.
04 - Cover the bowl with a damp towel or plastic wrap. Allow the dough to ferment at room temperature for 4 to 6 hours, or until approximately doubled in volume with visible bubbles on the surface.
05 - Turn the dough onto a lightly floured work surface. Gently degas and shape into a tight round or oval loaf, creating surface tension by folding the edges toward the center and sealing the seam underneath.
06 - Transfer the shaped dough seam-side up into a floured proofing basket (banneton) or a bowl lined with a heavily floured towel. Cover and refrigerate for 8 to 12 hours to develop flavor through cold fermentation.
07 - Place a Dutch oven with its lid on the center rack of the oven. Preheat to 450°F for at least 30 minutes to ensure the vessel is thoroughly heated.
08 - Gently invert the proofed dough onto a piece of parchment paper. Use a sharp bread lame or knife to score the top of the loaf with a single swift cut about ½ inch deep to control oven spring.
09 - Carefully lift the parchment paper and transfer the loaf into the preheated Dutch oven. Cover with the lid and bake for 20 minutes to create steam for a crisp crust.
10 - Remove the Dutch oven lid and continue baking for an additional 20 minutes until the crust develops a deep golden brown color and the loaf sounds hollow when tapped on the bottom.
11 - Transfer the baked loaf to a wire cooling rack. Allow to cool for at least 1 hour before slicing to ensure the crumb structure sets properly.