Instructions

• In a large bowl, mix 1/3 cup sourdough starter (90 g) and 1 1/2 cups water (346 g) with a fork until combined.
• Add 3 1/2 cups bread flour (520 g) and 2 teaspoons salt to the bowl. Mix with a spoon or your hands until a shaggy dough forms. You may need to use your hands to fully incorporate the flour.
• Cover the bowl with a damp cloth and let the dough rest for 30 minutes.
• Perform the first set of stretch-and-folds: with wet or lightly floured hands, reach under one side of the dough, gently stretch it upward and fold it over the top. Give the bowl a quarter turn and repeat three more times (four folds total per set).
• Cover the dough and rest 15–30 minutes. Repeat step 4 for a total of 3–4 sets (i.e., 3–4 rounds of four stretch-and-folds), covering and resting 15–30 minutes between each set.
• After the final set, cover the bowl and allow the dough to bulk ferment on the countertop for 7–10 hours, or refrigerate for up to 24 hours for slower fermentation. The dough should increase by about 50% (timing will vary with kitchen temperature).
• Lightly flour a work surface. Turn the dough out gently onto the surface and form it into a round by folding each side toward the center (stretch the top side up and fold into the center, rotate, and repeat until all sides are folded). Use a bench scraper or your hands to create surface tension by gently pushing and pulling the dough—only enough to tighten the round.
• Place a sheet of parchment in a bowl (or proofing basket) and dust the parchment lightly with flour. Place the shaped dough seam-side down on the parchment, cover, and refrigerate for 1 hour while you preheat the oven.
• Place your Dutch oven with its lid in the oven and preheat to 500°F. Allow the Dutch oven to heat for 50–60 minutes while the dough rests in the fridge.
• When ready to bake, remove the dough from the fridge. Using a sharp knife or razor blade, score the top of the dough at a 35–40° angle to about 1/2 inch deep.
• Carefully use the parchment as a sling to transfer the dough into the preheated Dutch oven. Immediately reduce the oven temperature to 450°F, cover the Dutch oven, and bake for 20 minutes.
• After 20 minutes, remove the lid and continue baking for another 20–25 minutes, until the crust is a deep golden brown and the internal temperature registers 205°–210°F.
• Remove the bread from the Dutch oven and cool on a cooling rack for at least 1 hour before slicing.