Overnight Sourdough Bread
Cold Ferment Method
Shape in the evening. Bake in the morning. This slow, cold-fermented loaf is the most flexible sourdough you’ll ever make — and arguably the best-tasting one too.
Why Cold Fermentation Makes Better Bread
Most sourdough problems — flat loaves, gummy crumb, bland flavour — come from rushing fermentation at room temperature. Cold fermentation solves all three, and the mechanism is worth understanding because it changes how you think about every bake you’ll ever do.
When your shaped dough goes into the fridge, yeast activity doesn’t stop — it slows dramatically. The lactic acid bacteria in your starter, however, are more cold-tolerant than the wild yeast. They keep producing organic acids at a lower rate throughout the chill. The result is a slow, steady accumulation of both lactic acid (the smooth, yoghurt-like sourness) and acetic acid (the sharper, vinegary tang) — the two compounds that give sourdough its signature complexity.
Gluten also benefits. The extended rest in cold conditions allows enzymatic activity to continue breaking down starches and relaxing the gluten network into a more extensible, gas-retaining structure. That’s why cold-proofed loaves often have better oven spring and a more open crumb than their same-day equivalents.
And then there’s the practical reality: a same-day sourdough requires you to be at home and attentive for 8–12 hours. An overnight sourdough requires about 45 minutes of active work, spread across two evenings. It fits around life in a way that all-day baking simply doesn’t.
Timing Options: Choose Your Schedule
One of the most common questions about this recipe is simply: when do I start? The answer depends entirely on when you want to eat fresh bread. Below are the three most practical schedules, but the bake planner below will calculate exact times for any target bake time you choose.
- Bread flour (strong)450g
- Whole wheat flour50g
- Water, room temp360ml
- Active sourdough starter75g
- Fine sea salt10g
Starter should be active and bubbly, 4–8 hrs after feeding. Using 15% starter keeps fermentation slow enough for a proper overnight retard.
- Mix (30 min autolyse). Combine flours and 330ml of the water. Mix until no dry flour remains. Cover and rest 30–60 minutes. This autolyse step transforms extensibility.
- Add starter and salt. Dissolve starter in remaining 30ml water, then add to dough along with the salt. Squeeze and fold until fully incorporated. Cover.
- Bulk ferment with stretch & folds. Over the next 4–5 hours, perform 4–5 sets of stretch & folds, spaced 30–45 minutes apart. Dough should rise 50–75% and feel airy.
- Pre-shape. Turn dough onto an unfloured surface. Using a bench scraper, fold into a rough round and drag toward you to build surface tension. Rest uncovered 25–30 minutes.
- Final shape. Shape into a tight boule or batard. Place seam-side up in a well-floured banneton. Cover with a shower cap or cling film.
- Cold retard. Refrigerate 8–16 hours (overnight). Do not cover airtight — the dough needs to breathe slightly.
- Preheat. Place Dutch oven inside your oven. Preheat at 250°C / 480°F for 45–60 minutes.
- Score and bake. Tip cold dough onto parchment. Score decisively, ½ inch deep at 45°. Lower into Dutch oven. Bake covered 20 min, then remove lid and bake 20–25 min until deep mahogany.
- Cool. Internal temp should reach 96–98°C / 205–208°F. Cool on a wire rack for a minimum of 1–2 hours before slicing.
Tell it when you want fresh bread. It works backwards and tells you exactly when to start, when to shape, and when to put the dough in the fridge.
Your Personalized Bake Plan
Weights adjusted for your starter inoculation rate.
Tips for the Best Overnight Sourdough
Getting the fermentation right
The most common failure point with overnight sourdough is over-fermentation during bulk. Because the dough will continue fermenting slowly in the fridge, you want bulk to finish slightly before the dough reaches full fermentation. Look for a 50–65% rise with bubbles visible on the sides and a slight dome on top — not 75–100% as you’d aim for with a same-day bake.
Temperature matters more than time
Bulk fermentation times vary enormously with kitchen temperature. At 18°C / 65°F, bulk might take 6–7 hours. At 26°C / 79°F, the same dough might be ready in 3.5 hours. Trust the visual signs, not the clock. The bake planner above accounts for this.
How long is too long in the fridge?
8–16 hours is the sweet spot. Up to 24 hours is workable if your fridge is genuinely cold (4°C / 39°F) and the dough wasn’t over-fermented going in. Beyond 24 hours the gluten network begins to degrade, leading to a flatter, denser loaf. If you’re unsure, do a poke test after 8 hours — it should feel pillowy and spring back slowly.
Why you should always bake from cold
Baking straight from the fridge isn’t just convenient — it’s better. Cold dough is firmer, scores more cleanly, and the dramatic temperature contrast going into the oven creates more oven spring than room-temperature dough does. Many bakers who’ve tried both methods go back to cold baking permanently.
Flour matters for overnight baking
Strong bread flour with at least 12–13% protein is important for overnight retards. Lower-protein flours can’t support the extended fermentation without gluten degrading. If you’re using all-purpose flour, add a small amount of vital wheat gluten (1 tsp per 500g) to compensate. The 10% whole wheat in this recipe isn’t just for flavour — the extra enzymes and natural sugars give the bacteria more to work with during the cold ferment.