01 - In a large bowl, mix bread flour and water until just combined. Cover and let rest for 1 hour.
02 - Add sourdough starter and sea salt to the autolysed dough. Mix thoroughly until fully cohesive and integrated.
03 - Perform 4 sets of stretch and folds at 30-minute intervals over 2 hours, keeping dough covered between sets to develop gluten structure.
04 - Cover bowl and let dough rise at room temperature for 4-6 hours until approximately doubled in volume.
05 - Turn dough onto lightly floured surface. Shape into a tight round or oval loaf, creating surface tension.
06 - Transfer shaped dough to floured proofing basket, seam side up. Cover and refrigerate for 8-12 hours.
07 - Preheat oven to 450°F with Dutch oven inside for at least 30 minutes.
08 - Gently invert dough onto parchment paper. Score top with sharp blade. Transfer with parchment into hot Dutch oven. Cover and bake 20 minutes.
09 - Remove Dutch oven lid and bake additional 20 minutes until crust is deep golden brown and internal temperature reaches 200°F.
10 - Transfer to cooling rack and let rest at least 1 hour before slicing to allow crumb structure to set.