Sourdough Boule
Naturally leavened round loaf built on a levain. Long warm bulk with folds, overnight retard in the banneton, then baked from cold for a blistered crust and a custardy open crumb.
Boule is French for ball, and it names the round loaf. Sourdough, a culture of wild yeast and bacteria, was the standard way to leaven bread for most of history, until brewer's barm and later industrial baker's yeast took its place. This loaf is raised by a starter alone.
The formula in numbers
- Hydration
- 75%
- Salt
- 2%
- Olive Oil
- none
- Portion
- 2 × 900 g
- Fermentation source
- Sourdough starter
- Bulk at room temperature
- 4 h 30 min
- In the fridge
- 12 h
- Final proof
- 1 h 30 min
- Flour strength
- W 260–320
- Flour protein
- 11.5–13.5%
How to prepare it
- Sourdough starter305 g flour, 305 g water610 g
- Flour712 g
- Water458 g
- Salt20 g
- W 260–320
The dough
Flour, water, salt and an active sourdough starter. The starter raises the loaf. Use a strong bread flour, W 260 to 320.
Feed the starter ahead of time and use it when it is bubbly and has risen. A sluggish starter makes a dense loaf.
- 75% water
Mixing
Mix the flour, water, starter and salt until no dry flour is left. At 75% hydration the dough is soft and a little sticky. It does not need long kneading: the folds in the next step build its strength.
The dough temperature after mixing sets the pace of fermentation. The calculator works out the water temperature for you.
- 4 h 30 min
Fermentation
4 h 30 min at room temperature. During the first half, stretch and fold the dough in its container every half hour or so. It is ready when it has grown, feels airy and shows bubbles along the sides.
Sourdough follows the temperature of your kitchen. Go by the dough, not only by the clock.
- 12 h
Shaping
Divide the dough into 2 pieces of 900 g. Round each one and let it rest, then shape it tight and set it seam up in a floured basket. Cover it and put it in the fridge for 12 h.
The cold night adds flavour and firms the dough, which makes it far easier to score.
- 35 min
Baking
The plan leaves 1 h 30 min between the fridge and the oven. Use it to heat a lidded cast-iron pot with the oven. Turn the loaf out, score the top and bake at around 230°C (446°F) for 20 min with the lid on, then at 220°C (428°F) for 15 min with the lid off.
No steam tray is needed. The closed pot holds the steam the loaf gives off.
The most common mistakes
Wrong:Mixing the dough with a starter that has not risen yet
Right:Feed it and wait until it is bubbly and clearly bigger.
Wrong:Ending the bulk by the clock alone
Right:Look for a dough that has grown and feels airy. A cool kitchen needs more time.
Wrong:Shaping the loaf loosely
Right:Tighten the surface as you shape. A taut skin holds the loaf up while it bakes.
Wrong:Cutting the loaf while it is hot
Right:Cool it on a rack first. The crumb is still setting and cuts gummy when hot.
Recommended flours
Flour for this formula: W 260–320, 11.5–13.5% protein. Ranked by fit, then by availability in your country, then by popularity.
