In a large mixing bowl, combine bread flour with warm water, stirring until a shaggy dough forms. Cover with a damp cloth and let it rest for 30 minutes.

After the autolyse, add active sourdough starter and salt. Mix until thoroughly combined.

Cover with a damp cloth again and let the dough rest at room temperature for 2 hours, performing a stretch and fold every 30 minutes.

Cover the bowl and allow the dough to rise for 6 to 8 hours at room temperature until doubled in size.

Transfer the dough to a floured surface and shape it into a round loaf. Place seam-side up in a proofing basket and refrigerate for 8 to 12 hours.

Preheat your oven to 450°F (232°C) with a Dutch oven inside for 30 minutes.

Carefully turn the dough onto parchment paper and score the top with a knife.

Remove the Dutch oven and lift the dough with parchment into the pot. Cover and bake for 20 minutes, then uncover and bake for an additional 25 minutes.

Transfer the loaf to a wire rack and allow it to cool completely before slicing.