Why Does My Sourdough Bread Keep Collapsing Common Mistakes And Fixes

Sourdough bread is a rewarding craft, but few things are more frustrating than pulling a beautifully proofed loaf from the oven only to watch it deflate into a dense pancake. Collapse can happen at any stage—during bulk fermentation, in the final proof, or even after baking. While sourdough is inherently unpredictable, consistent collapse is rarely bad luck. More often, it’s a signal of underlying issues in your process.

Understanding why your sourdough collapses means examining each phase of the bake: starter health, mixing technique, fermentation timing, shaping strength, and oven dynamics. This guide breaks down the most frequent causes of collapse and offers practical, tested solutions so you can build confidence and consistency in your baking.

1. Starter Strength and Fermentation Timing

Your sourdough starter is the engine of your loaf. If it's weak, underfed, or used at the wrong peak, your dough won’t have the gas-producing power needed for structure and rise.

A healthy starter should double predictably within 4–8 hours of feeding, with visible bubbles throughout and a tangy, pleasant aroma. Using a starter that hasn't peaked—or worse, has already fallen—means insufficient yeast activity. This leads to poor gas retention and eventual collapse during proofing or baking.

Tip: Feed your starter 4–6 hours before use and test its readiness by dropping a spoonful into water—if it floats, it’s ready.

Overfermentation is another major culprit. Leaving dough too long during bulk fermentation breaks down gluten, weakening the structure. The result? A sticky, slack dough that sags instead of holding shape. Signs include excessive bubbling, a strong alcoholic smell, and loss of elasticity.

“Sourdough isn’t about clock time—it’s about observing your dough. When it domes slightly and jiggles like jelly, it’s ready.” — Ken Forkish, Artisan Baker & Author

2. Gluten Development and Dough Strength

No matter how active your starter, without proper gluten development, your dough cannot trap gas effectively. Weak gluten leads to flat, collapsed loaves regardless of fermentation success.

Gluten forms through hydration and mechanical work—mixing, folding, and kneading. Underdeveloped dough lacks elasticity and tears easily when stretched. To test, perform the “windowpane test”: gently stretch a small piece of dough between your fingers. If it forms a thin, translucent membrane without tearing, gluten is sufficient.

Many home bakers skip or underperform folds during bulk fermentation. For medium-hydration doughs (70–75%), perform 3–4 sets of coil folds spaced 30 minutes apart during the first two hours of bulk fermentation. This builds strength gradually without overworking the dough.

Fold Type	Best For	Frequency
Coil Folds	High-hydration doughs (75%+)	Every 30 min, 3–4 times
Stretch & Fold	Medium hydration (65–75%)	Every 30 min, 3–4 times
Slap & Fold	Low hydration, beginner-friendly	Once, early in bulk

Conversely, overmixing or overfolding can also damage gluten. Dough that feels tight, dry, or resists further stretching may be overworked. Once gluten breaks down, recovery is difficult. Prevention is key—stop folding once the dough feels smooth, supple, and holds tension.

3. Shaping Technique and Final Proofing

Even well-fermented, strong dough can collapse if improperly shaped. Shaping creates surface tension—a taut outer skin that acts like a balloon, containing internal gases during proofing and oven spring.

Common shaping errors include:

• Not degassing sufficiently during preshape
• Rolling loosely instead of tightening the surface
• Using too much flour, preventing layers from adhering
• Transferring roughly into the banneton, breaking tension

To shape properly:

1. Preshape into a round and rest 20–30 minutes to relax gluten.
2. Flip seam-side up and flatten slightly into a rectangle.
3. Fold sides toward center, then roll tightly from bottom to top, sealing the seam.
4. Cup hands around the dough and rotate, tightening the surface until smooth and taut.

The final proof is equally critical. Overproofing is the leading cause of post-shape collapse. In an overproofed loaf, yeast exhausts available sugars, gas production slows, and gluten degrades. The dough becomes fragile and unable to support itself.

Tip: Perform the “poke test” to check proofing: lightly press the dough. If it springs back slowly and leaves a slight indent, it’s ready. If it doesn’t spring back, it’s overproofed.

Underproofed dough springs back quickly and may burst unpredictably in the oven. Overproofed dough barely springs back and often collapses when moved. Cold-proofing in the refrigerator (retarding) helps control fermentation and reduces risk of overproofing at room temperature.

Mini Case Study: Sarah’s Weekend Loaf Disaster

Sarah had been baking sourdough weekly for months. Her starter bubbled vigorously, and she followed recipes closely. But her loaves kept flattening after scoring. One Saturday, she left the final proof on the counter for 4 hours while running errands. When she returned, the dough was spread out like a pancake in the banneton.

She adjusted by shortening the final proof to 2.5 hours and moving it to a cooler part of the kitchen. She also began using the fridge for overnight proofing. Within two weeks, her loaves held shape, scored cleanly, and rose evenly in the oven. The fix wasn’t a new recipe—it was tighter timing and temperature control.

4. Baking Dynamics: Oven Spring and Scoring

Oven spring—the rapid expansion during the first 15 minutes of baking—is where many collapsing loaves meet their fate. Poor heat, steam, or scoring can sabotage even a well-prepared dough.

If your oven isn’t hot enough, the dough heats too slowly, killing yeast before the crust sets. Aim for a preheated oven at 450°F–475°F (230°C–245°C) with a baking steel or Dutch oven to retain heat. A cold vessel absorbs energy, delaying spring.

Steam is essential for a flexible crust that allows expansion. Without it, the surface hardens too soon, trapping gas inside and causing blowouts or collapse. A Dutch oven naturally traps steam from the dough. If baking on a stone, place a metal tray below and pour 1 cup of boiling water at load time.

Scoring directs expansion. Poor cuts lead to random bursting, often along the side or bottom, which destabilizes the loaf. Use a sharp blade (lame or razor) at a 30-degree angle, 1/2 inch deep. Single or double slashes work best for boules; ear cuts create dramatic presentation but require precision.

Do’s and Don’ts of Scoring

Do	Don’t
Score decisively in one motion	Hesitate or saw back and forth
Aim for 1/2 inch depth	Make shallow or overly deep cuts
Slash at a shallow angle for ears	Cut straight down (weak expansion)
Score just before baking	Score too early and lose tension

5. Hydration, Flour Choice, and Environmental Factors

Hydration—the ratio of water to flour—plays a major role in structure. High-hydration doughs (80%+) are prized for open crumb but are harder to manage. They require stronger gluten development and careful handling. Beginners often jump into high hydration too soon, leading to collapse.

Start with 68–72% hydration using bread flour or a blend of bread and all-purpose flour. These flours have higher protein content, promoting better gluten formation. Whole grain flours absorb more water and ferment faster due to natural enzymes, requiring adjustments in time and hydration.

Environmental factors also impact results. Warm kitchens accelerate fermentation; cool ones slow it. Humidity affects flour absorption. Weigh all ingredients—never measure by volume—for consistency. A kitchen scale accurate to 1 gram is non-negotiable for reliable baking.

Tip: Adjust water by +5% in dry climates or -5% in humid conditions to maintain dough feel.

Step-by-Step Guide to Prevent Collapse

Follow this sequence to minimize failure points:

1. Feed starter 4–6 hours before mixing. Confirm peak activity with float test.
2. Mix dough to initial cohesion. Autolyse (rest) 30 minutes before adding salt and starter.
3. Bulk ferment 3–5 hours with 3–4 sets of folds in the first half. Stop when dough is puffy, domed, and passes windowpane test.
4. Shape gently with firm surface tension. Let rest 20 minutes if resisting.
5. Final proof: 2–4 hours at room temp or 10–14 hours refrigerated. Use the poke test.
6. Preheat oven 45 minutes with Dutch oven or baking steel inside.
7. Score confidently, transfer quickly, and cover to retain moisture.
8. Bake covered 20 minutes, uncovered 20–25 minutes until internal temp reaches 205°F–210°F (96°C–99°C).

FAQ

Why does my sourdough collapse after I score it?

Scoring too deeply, using a dull blade, or overproofing are the most likely causes. Scoring releases tension—if the dough is already fragile from overproofing, it will deflate. Ensure your dough is well-structured and score with a swift, sharp motion.

Can I save a collapsed sourdough loaf?

If caught early during proofing, reshape and reproof in the fridge for 4–6 hours. If it collapses in the oven, it’s likely too late—but the flavor may still be excellent. Slice and toast it; many collapsed loaves make great sourdough croutons or breadcrumbs.

Is whole wheat sourdough more prone to collapse?

Yes. Whole wheat flour contains bran, which cuts gluten strands and speeds fermentation. Use a blend (e.g., 20–30% whole wheat) and shorten bulk fermentation by 30–60 minutes. Pre-soaking the whole grains (a soaker) can improve texture and strength.

Conclusion

Sourdough collapse isn’t inevitable—it’s informative. Each deflated loaf tells you something about your starter, technique, or environment. By systematically addressing fermentation, gluten development, shaping, and baking, you turn frustration into mastery.

The best bakers aren’t those who never fail, but those who learn from every flat loaf. Refine your process, trust your senses over the clock, and embrace the rhythm of the dough. With attention and adjustment, you’ll pull consistently beautiful, airy sourdough from your oven—one resilient rise at a time.

💬 What’s your biggest sourdough challenge? Share your experience or ask questions in the comments—let’s troubleshoot together and grow as a baking community.