1. Activate Your Sourdough Starter: The day before baking, feed your sourdough starter and let it become active and bubbly. It should double in size and pass the float test (a small spoonful floats in water). This ensures it has the strength to lift your dough.

2. Combine Water and Starter: In a large mixing bowl, gently whisk together your active sourdough starter and room temperature water until the starter is mostly dissolved. This creates the base for your dough.

3. Add Flour and Salt: Stir in your chosen flour (a blend of unbleached all-purpose and bread flour is excellent for softness) and salt. Mix with a spoon or your hands until no dry streaks of flour remain. The dough will be shaggy and sticky at this stage.

4. Autolyse (Resting Period): Cover the bowl and let the dough rest for 30 minutes to an hour. This “autolyse” step allows the flour to fully hydrate and gluten development to begin naturally, contributing to a softer crumb later.

5. Perform Stretch and Folds: Over the next 2-3 hours, perform 3-4 sets of stretch and folds. Every 30-45 minutes, gently stretch a portion of the dough up and fold it over itself, rotating the bowl each time. This builds strength without overworking the dough, which is vital for softness. The dough will become smoother and more elastic with each set.

6. Bulk Fermentation: After the stretch and folds, let the dough continue to ferment at room temperature until it has increased in volume by about 30-50% and feels airy. This could take anywhere from 3-6 hours depending on your starter’s activity and room temperature.

7. Shape Your Loaf: Gently turn the dough out onto a lightly floured surface. Shape it into your desired loaf shape (round or oval), being careful not to degas it too much. A gentle touch here helps maintain the airy structure.

8. Proofing (Cold Fermentation): Place the shaped dough into a floured banneton or a bowl lined with a floured tea towel. Cover and refrigerate for 8-12 hours (or up to 24 hours). Cold proofing develops flavor and makes the dough easier to handle.

9. Baking: Preheat your oven with a Dutch oven inside to 450 F (232 C) for at least 30 minutes. Carefully transfer the cold dough into the hot Dutch oven, score the top with a sharp blade, and bake with the lid on for 30 minutes. Remove the lid and bake for another 15-20 minutes, or until the crust is golden brown and the internal temperature reaches 200-210 F (93-99 C).

10. Cool Completely: This is critical for softness! Transfer the baked loaf to a wire rack and let it cool for at least 1-2 hours before slicing. Slicing too early can lead to a gummy texture.