Why Does My Sourdough Bread Collapse During Baking And How To Fix It For Good

Sourdough bread is one of the most rewarding bakes in the kitchen—when it works. But few things are more disheartening than watching your carefully crafted loaf rise beautifully in the oven only to sink into a dense, flat mess by the end of the bake. This collapse isn’t random; it’s a symptom of underlying issues in fermentation, structure, or technique. The good news? With the right understanding and adjustments, you can prevent collapse permanently and consistently produce tall, open-crumbed loaves with confidence.

Understanding Why Sourdough Collapses

A collapsing sourdough loaf typically means the internal structure couldn't support the expansion happening during oven spring. While some slight settling is normal, a dramatic collapse—especially after strong initial rise—indicates a failure in gluten development, overproofing, or improper scoring. Unlike commercial yeast breads, sourdough relies entirely on natural fermentation and physical dough strength, making it more sensitive to imbalances.

The primary causes fall into three categories: biological (over- or under-fermentation), mechanical (gluten weakness or poor shaping), and thermal (oven environment). Addressing each systematically will help you isolate and correct the root cause.

Tip: Perform the \"poke test\" gently—if your finger leaves a deep, slow-to-recover dent, the dough is likely overproofed.

Common Causes and How to Fix Them

1. Overproofing: The Silent Loaf Killer

Overproofing is the leading cause of collapse. When dough ferments too long, the gluten network breaks down from prolonged exposure to acids and gas. The structure weakens, unable to hold its shape during baking. Even if the dough looks puffy and full of gas, it may lack resilience.

This often happens when ambient temperatures are warmer than expected, or when bakers rely solely on time rather than visual cues. A dough that has doubled in bulk may still be underproofed if the gluten is strong and active, while another that looks slightly risen might already be overproofed if the starter was very active.

“Proofing isn’t about the clock—it’s about the dough’s readiness. Learn to read its texture, elasticity, and volume.” — Daniel Leader, author of Bread Alone

Solution: Reduce bulk fermentation or final proof time. Use cooler environments (like the refrigerator) for longer, slower proofing, which strengthens flavor without sacrificing structure. Always check for jiggly, wobbly dough—a sign it’s past its prime.

2. Weak Gluten Development

Gluten is the scaffolding of your loaf. Without sufficient development, the dough can’t trap gas effectively. This leads to rapid expansion followed by structural failure. Low-protein flour, insufficient mixing, or skipping stretch-and-folds contribute to this issue.

Inadequate gluten also results in a sticky, slack dough that spreads instead of holding height. High-hydration doughs (75% and above) are especially prone to collapse if the gluten isn’t properly developed.

Solution: Use bread flour (12–13% protein) for better gluten formation. Incorporate regular stretch-and-folds during bulk fermentation—every 30 minutes for the first two hours. Autolyse (resting flour and water before adding salt and starter) improves extensibility and strength.

3. Poor Shaping Technique

Shaping creates surface tension, which helps the loaf retain its height. If shaping is too loose or uneven, the dough spreads sideways instead of rising upward. A poorly shaped boule may open unpredictably during baking, causing one side to burst and the loaf to lean or collapse.

Solution: Practice tight shaping. After preshaping, let the dough rest 15–20 minutes (bench rest), then shape again with firm, confident motions. Rotate the dough as you tuck and tighten the surface. The final loaf should feel taut, like a balloon filled with air.

Tip: Use a well-floured banneton with proper orientation—seam side up for bâtards, down for boules—to support the shape during proofing.

4. Inadequate Scoring

Scoring controls where the bread expands. Unscored or shallow cuts force steam and gas to escape through weak points, often causing blowouts or sudden deflation. Deep, decisive slashes guide expansion and preserve structure.

Solution: Score with a razor-sharp blade (lame or utility knife) at a 30–45° angle, about ½ inch deep. Make swift, confident cuts. For round loaves, a single deep slash or classic “tic-tac” pattern works well. Avoid dragging the blade, which can tear the surface.

5. Oven and Steam Issues

Oven spring—the rapid rise in the first 10–15 minutes of baking—depends on heat, moisture, and oven stability. If the oven isn’t hot enough, or lacks steam, the crust forms too quickly, restricting expansion. Conversely, excessive steam without adequate ventilation can soften the crust too much, leading to instability.

Solution: Preheat your oven and baking vessel (Dutch oven or combo cooker) for at least 45 minutes at 450–500°F (230–260°C). Add steam via a preheated Dutch oven lid or tray of ice cubes. Release steam halfway through baking to allow proper crust formation.

Step-by-Step Guide to Prevent Collapse

Follow this timeline to build a resilient loaf from start to finish:

1. Autolyse (30–60 min): Mix flour and water; let rest. Enhances gluten without overworking.
2. Add Starter & Salt: Mix thoroughly, then begin stretch-and-folds every 30 minutes for 2–3 hours.
3. Bulk Fermentation: Let rise until 20–30% increase in volume, with bubbles and slight jiggle. Typically 3–5 hours at 75°F (24°C).
4. Preshape: Shape loosely into a round, rest 15–20 minutes on a floured surface.
5. Final Shape: Create tight surface tension. Place seam-side up in floured banneton for boules.
6. Final Proof: 1–2 hours at room temp or overnight in fridge. Dough should spring back slowly when poked.
7. Preheat: Heat oven and vessel to 475°F (245°C) for 45+ minutes.
8. Score & Bake: Transfer dough, score deeply, cover, bake 20 min. Uncover, reduce heat to 425°F (220°C), bake 20–25 min more.
9. Cool: Wait at least 1 hour before slicing to prevent gummy texture and structural stress.

Checklist: Prevent Sourdough Collapse

• ✅ Use high-protein bread flour (12–13%)
• ✅ Perform 4–6 sets of stretch-and-folds during bulk fermentation
• ✅ Monitor dough, not just time—stop bulk ferment when dough is cohesive and airy
• ✅ Preshape and bench rest before final shaping
• ✅ Shape with strong surface tension
• ✅ Proof in a lined, floured banneton with proper orientation
• ✅ Test readiness with the poke test—should spring back slowly
• ✅ Preheat oven and baking vessel thoroughly
• ✅ Score deeply (½ inch) with a sharp blade at an angle
• ✅ Bake covered for oven spring, uncovered for crust development
• ✅ Cool completely before slicing

Do’s and Don’ts Table

Do’s	Don’ts
Use a mature, active starter that doubles within 4–6 hours	Use a sluggish or hooch-covered starter
Proof in the fridge for better control and flavor	Leave dough out overnight in a warm kitchen without monitoring
Score with confidence and depth	Make hesitant, shallow cuts
Let dough cool fully before cutting	Slice into a hot loaf—steam release weakens structure
Use a Dutch oven for consistent steam and heat	Bake on a sheet pan without steam in a standard oven

Real Example: From Flat Loaf to Perfect Rise

Sarah, a home baker in Portland, struggled for months with collapsed loaves. Her dough looked perfect—bubbly, doubled, and elastic—but always sank in the oven. She assumed she needed more hydration or a hotter oven. After consulting a local bakery, she realized her starter was peaking too early, and her final proof was running 2 hours too long.

She adjusted by feeding her starter earlier in the day, reducing bulk fermentation by 45 minutes, and switching to a cold final proof. She also refined her shaping technique, focusing on surface tension. On her next bake, the loaf rose evenly, held its shape, and cracked open beautifully along the score line. No collapse. “I was chasing the wrong problem,” she said. “It wasn’t the oven—it was the timing.”

Frequently Asked Questions

Can I rescue an overproofed loaf?

Yes, but with limitations. Gently reshape the dough and refrigerate for 2–4 hours to re-tighten the gluten. This won’t fully restore strength, but it can salvage some volume. Baking immediately usually results in collapse.

Why does my loaf rise in the oven and then fall?

This is classic overproofing. The dough expands rapidly during oven spring, but the weakened gluten can’t sustain the pressure. The gas escapes, and the structure collapses. Tighten your fermentation window and use the fridge to slow the process.

Does hydration level affect collapse?

Absolutely. Higher hydration (above 78%) increases difficulty because wetter doughs are harder to strengthen. Beginners should start with 70–75% hydration using bread flour to build skills before advancing.

Maintaining Consistency: Track Your Bakes

One of the most effective ways to eliminate collapse is to keep a sourdough journal. Record:

• Starter maturity and feed time
• Flour type and hydration
• Bulk fermentation duration and temperature
• Proofing method (room temp vs. fridge)
• Shaping tightness
• Oven temp and vessel used
• Final result (rise, crumb, collapse)

Patterns emerge quickly. You’ll notice, for example, that above 78°F (26°C), your dough needs 30% less time. Or that a 12-hour cold proof gives better structure than a 3-hour room proof. Data beats guesswork every time.

“The best sourdough bakers aren’t the ones with the fanciest ovens—they’re the ones who pay attention.” — Ken Forkish, The Elements of Pizza

Conclusion: Build Confidence, One Loaf at a Time

Sourdough collapse isn’t a flaw in you—it’s feedback from the dough. Each failed loaf teaches you more about fermentation, strength, and timing. By addressing overproofing, improving gluten development, refining shaping, and mastering oven dynamics, you’ll turn inconsistency into mastery.

Start small: focus on one variable at a time. Nail your starter routine. Perfect your folds. Then refine your bake. Soon, you’ll pull golden, crackling loaves from the oven with predictable success. The reward isn’t just great bread—it’s the quiet pride of knowing exactly how you made it happen.

💬 What’s your biggest sourdough challenge? Share your experience or ask questions in the comments—let’s troubleshoot together and help others avoid the same pitfalls.