Sourdough Bread

Part 1: Bulk Fermentation (4–6h at ≈24–26°C)

1. In a large bowl, mix 100 g starter with 425 g water until mostly dissolved.
2. Add 250 g bread flour, 250 g whole wheat flour, and 20 g salt. Mix until no dry flour remains.
3. Knead for 10–15 seconds to bring together into a rough dough.
4. Let rest 30–60 minutes (autolyse).
5. Perform 3–4 sets of stretch & folds every 30–60 minutes during the first 2–3 hours.
6. End bulk when dough has increased by 50–75% in volume, feels airy, and jiggles slightly.

Part 2: Shaping & Cold Proof (12–24h at 4°C)

1. Lightly flour your work surface and hands.
2. Gently turn out the dough.
3. Preshape into a loose round, cover, and rest 20–30 minutes.
4. Final shape: flip over carefully to avoid de-gassing. Fold the bottom up to center, stretch the left side ¾ to the right, fold the right side over the left, then stretch and fold the top down to center. Pinch from the sides and overlap in the center from top, middle, and bottom, then carefully roll from bottom to top.
5. Place seam-side up in a floured proofing basket.
6. Cover with a shower cap or bag and refrigerate for 12–24 hours.

Part 3: Bake (50–60 min at 275°C → 220°C)

1. Oven setup: Arrange racks before preheating — bottom rack: empty metal tray or cast iron pan (steam), middle rack: baking tray or stone (dough), upper rack: cast iron pan or tray placed 5–8 cm above dough (heat shield).
2. Preheat: Preheat oven to 275°C, top/bottom heat only (no fan). Allow at least 45 minutes.
3. Score & load: Take dough from fridge and score deeply with a curved blade at a 30–45° angle. Transfer to preheated tray/stone on middle rack (use baking paper if needed).
4. Steam: Pour 250 ml boiling water into the hot steam tray on the bottom rack. Close oven immediately to trap steam.
5. Bake with steam: Bake 30 minutes at 250°C with steam and shield in place — do not open oven.
6. Finish: Remove steam tray carefully. Optionally remove top shield for deeper browning. Lower oven to 220°C and bake 20–30 more minutes until dark mahogany (96–99°C internal).

Part 4: Cool (1–2h)

1. Transfer bread to a wire rack.
2. Let cool at least 1–2 hours before slicing for best texture.

Schedule

Day 1

Time	Action
9:30 AM	Mix starter + water, add flours + salt, knead briefly. Autolyse 30–60 min
10:30 AM	Stretch & fold #1
11:30 AM	Stretch & fold #2
2:30 PM	Stretch & fold #3
4:00 PM	Pre-shape, rest 20–30 min
4:30 PM	Final shape → into proofing basket → fridge

Day 2

Time	Action
9:30 AM	Preheat oven to 275°C with steam tray, baking stone/tray, and top shield
10:15 AM	Score dough, load onto middle rack, add steam. Bake 30 min at 250°C
10:45 AM	Remove steam tray. Lower to 220°C, bake 20–30 min
11:15 AM	Transfer to wire rack. Cool 1–2 hours before slicing