1. 1. Mixing Your Dough and Initial Rest: Combine your active sourdough starter, water, flour, and salt in a large bowl. Mix until just combined and no dry flour remains. Cover the bowl and let it rest for 30 minutes to an hour. This initial rest, called autolyse or rest period, allows the flour to fully hydrate.

2. 2. Beginning Bulk Fermentation with Folds: After the rest, begin your bulk fermentation. This stage typically lasts several hours at room temperature. During this time, you’ll perform a series of “stretch and folds” or “coil folds” every 30-60 minutes for the first 2-3 hours. Gently stretch a portion of the dough up and fold it over itself, rotating the bowl as you go. This develops gluten and builds strength.

3. 3. Monitoring Dough Development During Bulk Fermentation: Observe your dough closely. It should become smoother, more elastic, and increase significantly in volume, typically by 30-50% for a well-fermented dough. Look for signs of fermentation, such as small bubbles on the surface and a jiggly, airy texture. The “windowpane test” (stretching a small piece of dough until it’s translucent without tearing) can indicate sufficient gluten development.

4. 4. Shaping Your Dough for Cold Proofing: Once bulk fermentation is complete, gently turn your dough out onto a lightly floured surface. Shape it into your desired form (round or oval) with minimal handling to preserve the trapped gases. This shaping creates surface tension, which is crucial for a good oven spring.

5. 5. Preparing for the Cold Proof: Transfer your shaped dough into a floured banneton (proofing basket) or a bowl lined with a floured towel, seam-side up. Cover it with plastic wrap or a damp cloth to prevent it from drying out.

6. 6. The Cold Proofing Stage: Place your covered dough in the refrigerator (usually 38-40 F / 3-4 C) for 12 to 48 hours. This cold environment significantly slows down fermentation, allowing complex flavors to develop and making the dough easier to handle. The dough will continue to slowly rise and firm up.

7. 7. Baking After Cold Proofing: When you’re ready to bake, preheat your oven with a Dutch oven inside. Carefully remove the dough from the refrigerator, invert it into the hot Dutch oven, score it, and bake according to your recipe’s instructions. The cold dough holds its shape better and often results in a better oven spring.