Why Does My Sourdough Bread Collapse In The Oven Pro Tips To Fix It

Sourdough baking is as much science as it is art. When your loaf rises beautifully during proofing only to deflate dramatically in the oven, it’s not just disappointing—it can feel like a mystery. Yet, collapsed sourdough isn’t random. It’s usually the result of one or more preventable factors related to dough strength, fermentation, structure, or heat management. Understanding why this happens—and how to fix it—can transform inconsistent results into reliable, bakery-quality loaves.

Whether you're a weekend baker or refining your craft, mastering the causes behind oven collapse gives you control over the final rise, crumb, and crust. This guide breaks down the most common culprits and delivers actionable, professional-level solutions to help you achieve that coveted oven spring without the dreaded sink.

Understanding Oven Spring and Why Collapse Happens

Oven spring refers to the rapid expansion of dough during the first 10–15 minutes of baking, driven by trapped gases (mainly carbon dioxide) expanding under heat and steam creating a moist environment that keeps the crust flexible. A strong gluten network holds these gases until the structure sets through starch gelatinization and protein coagulation.

When a loaf collapses, it means the internal structure couldn’t withstand the pressure of gas expansion. Instead of rising upward, the dough spreads sideways or sinks in the center. This often occurs due to:

• Over-fermentation weakening gluten
• Poor shaping leading to weak surface tension
• Inadequate scoring restricting expansion
• Baking at too low a temperature
• Degassing during transfer or loading

The key is not just avoiding collapse but building resilience into every stage of the process—from mixing to baking.

Tip: Perform the \"poke test\" gently. If the dough doesn't spring back at all, it's overproofed. If it springs back quickly, it needs more time. Ideal response: slow rebound leaving a slight indentation.

Common Causes of Sourdough Collapse (and How to Fix Them)

1. Over-Fermentation Weakens Gluten Structure

One of the top reasons for collapse is overproofing. As fermentation progresses, yeast and bacteria produce acids that gradually break down gluten. While some acidity enhances flavor, excessive breakdown compromises structural integrity.

An overproofed dough lacks elasticity. It may look puffy and feel fragile, collapsing easily when handled or exposed to oven heat. The gases have nowhere to go but outward, causing lateral spread or central deflation.

“Gluten is the scaffolding of your loaf. Once it starts dissolving from prolonged fermentation, no amount of scoring will save it.” — Daniel Leader, author of *Local Breads*

Solution: Monitor bulk fermentation closely. Use time, temperature, and visual cues together. Dough should rise 30–50% in volume, feel airy but still taut, and pass the fingertip poke test with moderate resistance. In warm kitchens, shorten fermentation times or use cooler water.

2. Poor Shaping Creates Weak Surface Tension

Shaping isn’t just about aesthetics—it’s critical for creating surface tension that contains gas during proofing and baking. A poorly shaped loaf has loose seams or uneven skin, making it prone to bursting unpredictably or failing under internal pressure.

If the surface is slack, the dough expands where resistance is lowest, often splitting along weak spots instead of controlled scores. This uncontrolled release leads to partial collapse.

Solution: Practice tight shaping techniques. After preshaping, let the dough rest for 15–20 minutes to relax the gluten. Then, stretch and fold the dough tightly toward the center, rotating and sealing the seam underneath. Use the bench slightly tacky to allow friction while shaping. Finish with a smooth, taught top surface.

3. Inadequate or Incorrect Scoring

Scoring controls where and how the bread expands. Without proper slashes, pressure builds internally until it ruptures at the weakest point—often causing blowouts or collapse.

Too shallow cuts won’t open fully; too deep ones cut through the tensioned skin, releasing pressure prematurely. Angled cuts (about 30 degrees) allow better \"ear\" formation and cleaner expansion.

Tip: Use a sharp lame or razor blade. Dull tools drag instead of slicing cleanly, tearing the dough and compromising structure.

4. Baking in a Cold or Uneven Oven

Oven temperature directly affects oven spring. If the oven isn’t hot enough (below 450°F / 230°C), the dough heats too slowly. By the time the crust sets, much of the gas has already escaped, and the structure collapses before it stabilizes.

Additionally, ovens with poor heat retention or uneven distribution create hot and cold spots, leading to asymmetric expansion and localized collapse.

Solution: Preheat your oven for at least 45–60 minutes with a baking steel or stone inside. These materials absorb and radiate heat efficiently, mimicking professional deck ovens. Target 475°F (245°C) for standard sourdough.

5. Degassing During Transfer

Moving a delicate, proofed loaf from banneton to peel or pot can introduce shocks that release trapped gas. Dropping, tilting, or dragging the dough breaks bubbles and reduces lift potential.

This is especially problematic with high-hydration doughs (>75%), which are inherently more fragile.

Solution: Flip the dough confidently onto a well-floured peel. Use rice flour to prevent sticking without absorption. Slide it swiftly into the Dutch oven using a quick jerk motion. Avoid hesitation or repositioning after placement.

Pro Checklist to Prevent Sourdough Collapse

Follow this checklist before every bake to minimize risk of collapse:

1. ✅ Confirm starter is active and peaking (float test optional, but rise within 4–6 hours after feeding is ideal)
2. ✅ Limit bulk fermentation to 3–5 hours at room temp (adjust based on ambient temperature)
3. ✅ Preshape and final shape with firm surface tension; avoid tearing
4. ✅ Proof in a controlled environment (use fridge for longer, safer cold proof if needed)
5. ✅ Score decisively with a sharp blade at 30° angle, 1/2 inch deep
6. ✅ Preheat oven and baking vessel for at least 45 minutes
7. ✅ Transfer dough smoothly without jostling
8. ✅ Bake with steam for first 20 minutes (Dutch oven traps natural steam effectively)

Step-by-Step Guide to Building a Resilient Loaf

Follow this timeline to ensure structural integrity throughout the bake:

Stage	Action	Key Focus
0:00 – Mixing	Autolyse flour and water for 30 min; add salt and starter	Develop early gluten without overmixing
1:00 – Bulk Fermentation Start	Begin at room temperature (~75°F)	Monitor volume increase and texture hourly
1:30 – First Coil Fold	Gently lift and fold dough every 30 min for next 1.5 hrs	Build strength without degassing
3:00 – Preshape	Shape into round, rest 20 min uncovered	Prepare for final tension
3:20 – Final Shape	Tighten surface, seal seam, place in banneton	Maximize surface tension
3:30 – Final Proof	Room temp: 2–3 hrs; fridge: 8–16 hrs	Stop before full puffiness; aim for 50% rise
Bake Day – Preheat	Turn oven to 475°F with Dutch oven inside	Allow 60 min preheat for thermal saturation
Bake – Load & Score	Transfer, score immediately, cover, bake 20 min	Preserve gas; initiate clean expansion
Bake – Finish	Uncover, reduce heat to 450°F, bake 20–25 min	Set crust and color evenly

Real Example: From Flop to Flourish

María, an avid home baker in Portland, struggled for months with her sourdough consistently collapsing after a promising rise. Her dough looked perfect in the banneton—domed and airy—but sank within minutes of entering the oven.

She reviewed her process and realized she was letting her final proof go overnight at room temperature (up to 14 hours). The cool kitchen delayed fermentation early on, but once it warmed mid-proof, activity surged. By morning, the gluten was compromised.

Her fix? Switching to a refrigerated proof after just 1 hour at room temperature. She also tightened her shaping technique, focusing on creating a taught outer skin. Finally, she began preheating her Dutch oven for a full hour.

The result? Consistent oven spring, symmetrical bloom, and a resilient crumb. “I thought more fermentation meant more flavor,” she said. “But now I know balance is everything.”

Do’s and Don’ts of Sourdough Baking to Avoid Collapse

Do’s	Don’ts
Use a levain that peaks predictably	Use sluggish or past-peak starter
Proof in the fridge for better control	Leave dough out for extended room-temp proof
Score deeply and at an angle	Make timid, straight-down cuts
Preheat baking vessel thoroughly	Place dough in a cold or inadequately heated oven
Handle dough gently during transfer	Drop or shake the dough into the pot

Frequently Asked Questions

Can I rescue a collapsed sourdough loaf?

Once a loaf collapses in the oven, you can’t reverse it. However, the bread is still edible and often tasty. For future bakes, adjust proofing time or improve shaping. If the loaf collapses late in baking (after 25+ minutes), it may be due to excessive moisture or underbaking—try extending the final bake time.

Does hydration level affect collapse?

Yes. Higher hydration (above 78%) increases stickiness and fragility, making dough harder to shape tightly. While desirable for open crumb, it demands stronger gluten development and precise timing. Beginners should start with 70–75% hydration for better handling and stability.

Should I always use a Dutch oven?

A Dutch oven is highly recommended, especially for beginners. It traps steam naturally, promotes even heat distribution, and supports vertical rise. Alternatives like steam-injected ovens or covered clay pots work too, but a heavy lidded pot offers the most accessible path to reliable oven spring.

Final Tips for Consistent, Upright Loaves

Consistency in sourdough comes not from perfection in one step, but from precision across all stages. Think of your loaf as a system: each phase builds upon the last. A flaw in fermentation can’t be fixed by better scoring. A weak shape won’t hold up even in a perfectly hot oven.

Keep a baking journal. Note room temperature, fermentation duration, proofing conditions, and outcomes. Over time, patterns emerge that help you anticipate issues before they happen.

And remember: collapse doesn’t mean failure. It’s feedback. Every flat loaf tells you something about your process. Adjust one variable at a time, and soon you’ll bake with confidence, knowing exactly how to coax maximum rise from your dough.

💬 What’s your biggest sourdough challenge? Share your experiences or questions below—let’s troubleshoot together and help others rise higher!