01 - In a large bowl, combine the bread flour, whole wheat flour, and water, mixing until just incorporated. Cover the bowl and let rest for 1 hour to hydrate the flour.
02 - Add the active sourdough starter and sea salt to the autolyse mixture. Mix thoroughly by hand or with a spatula until fully incorporated and the dough begins to develop structure.
03 - Cover the dough and ferment at room temperature for 4 to 5 hours. Perform stretch and folds every 30 to 45 minutes, repeating the sequence 4 times to build dough strength.
04 - Turn the dough onto a lightly floured work surface. Gently shape into a round boule, cover, and let rest for 20 minutes to relax the gluten.
05 - Shape the dough into a tight round loaf, creating surface tension. Place seam side up in a well-floured proofing basket or lined bowl.
06 - Cover and let rise at room temperature for 2 to 3 hours until increased in volume. For enhanced sour flavor, refrigerate overnight for cold fermentation.
07 - Position a Dutch oven or heavy lidded pot in the oven. Preheat to 480°F for at least 30 minutes to ensure proper heat retention.
08 - Gently invert the dough onto parchment paper. Score the surface with a sharp blade or lame. Transfer to the preheated pot, cover with the lid, and bake for 20 minutes. Remove the lid, reduce temperature to 430°F, and continue baking for 25 minutes until deep golden brown.
09 - Remove the bread from the pot and transfer to a wire rack. Allow to cool completely before slicing to ensure proper crumb structure.