Ingredients
Levain
- 40 gmature sourdough starter, doubled and fed 8 hours before
- 80 gstrong white bread flour
- 80 gwater at 26°C (80°F)
Final dough
- 850 gstrong white bread flour, 12–13% protein
- 50 gwholemeal or dark rye flour
- 660 gwater at 24°C (75°F) (73% hydration)
- 20 gfine sea salt
- 50 gwater, held back for the salt
To bake
- Rice flour, for dusting the bannetons
- 1cast-iron Dutch oven or a baking stone plus a steam tray
Directions
- Build the levain 6–8 hours ahead and use it when it has domed and just begun to flatten in the centre, smelling sharply sour rather than sweet.
- Mix the flours with 660 g water and rest 45 minutes to autolyse; the dough will slacken and become extensible as the flour hydrates.
- Add the levain and squeeze it through, then 20 minutes later add the salt dissolved in the reserved 50 g water and work it in until the dough tightens and pulls cleanly from the bowl.
- Bulk ferment at 24–26°C (75–80°F) for 4–5 hours, giving four sets of stretch and folds in the first two hours. Stop when the dough has risen 50%, feels airy and domed, and shows bubbles at the sides of the tub.
- Divide, pre-shape into loose rounds and rest 25 minutes, then shape tightly into batards or boules with real surface tension and place seam up in rice-floured bannetons.
- Cold retard in the fridge at 4°C (40°F) for 14–18 hours. This long cold proof is where the acetic sourness that defines San Francisco loaves develops.
- Preheat the Dutch oven at 250°C (475°F) for 45 minutes. Turn the cold loaf out, score it decisively with a lame at a shallow angle, 1 cm deep.
- Bake covered at 250°C (475°F) for 20 minutes, then uncovered at 225°C (425°F) for 22–25 minutes until the crust is deep mahogany, almost bordering on burnt, and the internal temperature is 96–98°C (205–210°F).
- Cool on a rack at least 2 hours. Cutting into a warm sourdough gives a gummy crumb, because the starch is still setting.
Technique
- The sourness comes from the cold retard and a mature, slightly under-fed starter, not from adding anything. San Francisco starters host Fructilactobacillus sanfranciscensis, but the bacteria travel: a starter maintained the same way anywhere will behave similarly, and the local-air legend is largely marketing.
- Hydration is a target, not a rule. Different flours drink differently; hold back 50 g of water until you feel the dough.
- Bake it darker than feels comfortable. The blistered, near-black crust is the visual signature of the style and carries most of the flavour.
Substitutions
- No Dutch oven? Bake on a preheated stone with a tray of boiling water on the floor of the oven for the first 20 minutes, then remove it.
- Bread flour can be cut with up to 15% wholemeal for a more active ferment and a nuttier crumb, with slightly less rise.
Variations
- The classic round boule hollowed out as a clam chowder bread bowl on Fisherman’s Wharf.
- Sourdough batard with a longer, colder 24-hour retard for extra tang.
- Country loaf with 20% rye, darker and denser, sold across the Bay Area.
History
Gold Rush bakers carried starters from 1849; Boudin still bakes with one, and the bacterium Lactobacillus sanfranciscensis was named for the city in 1971.
Frequently asked questions
What is San Francisco sourdough?
San Francisco sourdough is a bread & pastry from United States: tangy, blistered white loaf leavened only with a wild starter. Gold Rush bakers carried starters from 1849; Boudin still bakes with one, and the bacterium Lactobacillus sanfranciscensis was named for the city in 1971.
How long does San Francisco sourdough take to make?
San Francisco sourdough takes 1 hr active of preparation and 24 hr fermentation, 45 min baking of cooking. The recipe makes 2 loaves. It is rated hard to make.
What can I substitute in San Francisco sourdough?
Yes, within limits. No Dutch oven? Bake on a preheated stone with a tray of boiling water on the floor of the oven for the first 20 minutes, then remove it. Bread flour can be cut with up to 15% wholemeal for a more active ferment and a nuttier crumb, with slightly less rise.
What is the most important thing to get right in San Francisco sourdough?
Build the levain 6–8 hours ahead and use it when it has domed and just begun to flatten in the centre, smelling sharply sour rather than sweet.
