Combine starter and water: In a large bowl, stir together the sourdough starter and filtered water until mostly dissolved.

Add flour and mix: Add the bread flour and stir until no dry bits remain. Cover with a towel and let sit for 30 minutes (autolyse).

Add salt and knead: Sprinkle salt over the dough and mix well by hand or using a stand mixer with a dough hook until combined.

Bulk fermentation and folding: Cover and let the dough rise at room temperature for 4–5 hours. During this time, perform a set of folds every 30–45 minutes.

Shape the dough: Lightly flour a work surface with rice flour. Shape dough into a round or oval loaf and place it seam-side up in a floured banneton or towel-lined bowl.

Cold proof overnight: Cover the banneton and refrigerate for 8–12 hours.

Fire the oven: Heat the wood-fired oven to 500°F (260°C), then let it cool to around 450°F (230°C). Preheat Dutch oven inside.

Score and bake: Turn dough onto parchment, score with a sharp blade, and place into the hot Dutch oven. Bake covered for 20 minutes, then uncovered for another 20–25 minutes.