Why Does My Sourdough Bread Collapse In The Oven Baking Fixes That Work

Sourdough baking is both an art and a science, and few things are more frustrating than watching your carefully crafted loaf rise beautifully in the oven—only to deflate moments later. A collapsed sourdough isn’t just visually disappointing; it often signals structural issues that affect texture and flavor. While oven spring is one of the most exciting parts of baking, when that rise reverses, it’s usually due to preventable mistakes in fermentation, shaping, scoring, or oven conditions.

Understanding why this happens—and how to fix it—is essential for bakers at any level. The good news: with targeted adjustments, you can consistently achieve a well-risen, open-crumbed sourdough loaf that holds its shape from oven to cooling rack.

Understanding Why Sourdough Collapses During Baking

When a sourdough loaf collapses in the oven, it typically occurs during or immediately after the peak of oven spring—the rapid expansion caused by trapped gases expanding under heat. This collapse indicates that the dough’s structure couldn’t support the internal pressure, leading to deflation. Several interrelated factors contribute to this failure:

• Overfermentation: If the dough ferments too long, gluten breaks down and gas retention weakens.
• Poor gluten development: Inadequate kneading or folding results in weak dough structure.
• Underproofed or overproofed dough: Both extremes compromise stability during baking.
• Inadequate scoring: Poor cuts restrict expansion, causing uneven bursting and collapse.
• Oven temperature fluctuations: A drop in heat mid-bake reduces steam pressure needed for lift.
• Lack of preheated baking vessel: Cold Dutch ovens absorb heat, delaying oven spring.

The key is diagnosing which factor—or combination—is affecting your bake. Once identified, corrective steps can be taken with precision.

Tip: Perform the \"poke test\" before baking: gently press the dough. If it springs back slowly and leaves a slight indentation, it's ready. If it doesn't spring back, it's overproofed.

Fix 1: Optimize Fermentation Timing and Temperature

Fermentation is the foundation of sourdough success. Overfermentation is one of the most common causes of collapse. As wild yeast consumes flour sugars, it produces carbon dioxide and alcohol. Prolonged fermentation weakens gluten networks through enzymatic activity, especially if the dough gets too warm (above 78°F / 25°C).

To maintain structural integrity:

1. Monitor ambient temperature using a digital thermometer.
2. Adjust bulk fermentation time based on temperature—cooler environments require longer proofing.
3. Use refrigerator retardation for final proof to slow fermentation and enhance flavor without risking overproofing.

A typical room-temperature bulk fermentation lasts 4–5 hours at 75°F (24°C), followed by a shaped final proof of 1–2 hours at room temp or 12–16 hours in the fridge. Cold fermentation strengthens dough resilience and gives better control over timing.

“Temperature management is non-negotiable in sourdough. Even a 5-degree difference can shift fermentation by an hour.” — Dr. James Thompson, Artisan Bread Researcher, UC Davis

Fix 2: Strengthen Gluten Development Through Proper Technique

Gluten forms the elastic framework that traps gas bubbles during fermentation and baking. Without sufficient strength, the dough cannot withstand internal pressure when heated.

Key techniques to improve gluten development:

• Autolyse: Mix flour and water and let rest for 30–60 minutes before adding starter and salt. This allows hydration and initial gluten formation without mechanical stress.
• Stretch and folds: Perform 3–4 sets during bulk fermentation (every 30 minutes in the first two hours). Gently pull and fold the dough over itself to align gluten strands.
• Windowpane test: After bulk fermentation, pinch and stretch a small piece of dough. If it stretches thin enough to transmit light without tearing, gluten is well-developed.

Dough made with high-extraction or whole grain flours may require extra folds due to bran interference with gluten formation. Consider blending in 10–20% bread flour to boost strength while maintaining flavor complexity.

Fix 3: Perfect Your Scoring Technique

Scoring isn’t just decorative—it’s functional. Controlled slashes guide where the loaf expands during oven spring. Poorly executed cuts lead to unpredictable bursting, often along weak points, which destabilizes the entire structure.

Scoring Mistake	Consequence	Solution
Shallow cuts	Restricted expansion, pressure builds internally	Cut ¼ to ½ inch deep with a sharp blade
Blunt knife or dull lame	Tearing instead of clean slicing	Use a razor blade or curved lame
Incorrect angle (too vertical)	Flaps don’t peel back properly	Hold blade at 30–45° angle to create “ear”
Delayed scoring	Dough skin dries, resists opening	Score right before loading into oven

Aim for confident, continuous strokes. For round loaves (boules), a single deep cross or spiral works well. For batards, use a single slash or classic “tic-tac” pattern. Practice on spare dough to refine hand pressure and blade control.

Fix 4: Control Oven Environment for Maximum Lift

The first 20 minutes of baking are critical. Steam keeps the crust soft and flexible, allowing maximum expansion. A sudden loss of heat or moisture halts oven spring and risks collapse.

To optimize oven performance:

• Preheat your Dutch oven or baking steel for at least 45 minutes at 450°F (230°C).
• Bake with lid on for the first 20 minutes to trap steam.
• Remove lid and reduce heat to 425°F (220°C) for remaining 20–25 minutes to dry the crust.
• Avoid opening the oven door early—temperature drops disrupt expansion.

If you don’t have a Dutch oven, create steam by placing a metal tray on the bottom rack and pouring 1 cup of boiling water into it just after loading the loaf.

Tip: Always place the dough seam-side up when transferring to a preheated Dutch oven—it flips automatically when closed, protecting the surface.

Mini Case Study: From Flat Loaf to Bakery-Quality Rise

Marie, a home baker in Portland, struggled for months with collapsing sourdough. Her loaves would dome impressively at first, then sink dramatically by minute 15. She used a 100% hydration starter and fermented her dough 5 hours at room temperature before shaping and proofing another 3 hours.

After reviewing her process, she realized her kitchen was running hot (80°F / 27°C), accelerating fermentation. She also wasn’t performing stretch and folds and scored her bread with kitchen scissors, creating jagged tears.

Her turnaround plan:

1. Reduced bulk fermentation to 3.5 hours with three sets of stretch and folds.
2. Final proofed in the fridge overnight (retarded proof).
3. Switched to a razor blade for scoring at a 45° angle.
4. Preheated a cast-iron Dutch oven for 50 minutes.

Within two bakes, her loaves achieved consistent oven spring with no collapse. The crumb opened beautifully, and the crust developed a glossy ear—a hallmark of proper scoring and steam control.

Step-by-Step Guide to Prevent Collapse

Follow this sequence to ensure structural stability from mix to finish:

1. Mix and autolyse: Combine flour and water; rest 45 minutes.
2. Add starter and salt: Mix thoroughly, then begin bulk fermentation.
3. Perform stretch and folds: 3–4 sets over 2 hours.
4. Shape gently: Pre-shape, rest 20 minutes, then final shape with tension.
5. Proof strategically: Room temp for 1–2 hours or refrigerate for 12–16 hours.
6. Preheat vessel: Dutch oven or baking steel at 450°F for 45+ minutes.
7. Score decisively: Use sharp blade at correct depth and angle.
8. Bake covered: 20 minutes with lid on for steam.
9. Bake uncovered: 20–25 minutes until internal temp reaches 205–210°F (96–99°C).
10. Cool completely: Wait at least 2 hours before slicing to preserve structure.

This method prioritizes controlled fermentation, strong gluten, and optimal heat transfer—each crucial for preventing collapse.

Common Myths About Sourdough Collapse

Misinformation often leads bakers down unproductive paths. Here are some myths debunked:

• Myth: More starter means better rise.
  Truth: Excess starter accelerates fermentation and weakens structure. Stick to 20–25% of total flour weight.
• Myth: Denser dough won’t collapse.
  Truth: Underproofed dense dough lacks gas for oven spring and may still burst unpredictably.
• Myth: All collapse happens in the oven.
  Truth: Some deflation occurs during transfer. Handle shaped loaves gently and use proper banneton support.

FAQ: Common Questions About Sourdough Collapse

Why does my sourdough deflate when I put it in the oven?

This often means the dough was overproofed. The gluten network is already weakened, so the shock of heat causes immediate collapse. Ensure your final proof isn’t too long—use the poke test to verify readiness.

Can I save a collapsed sourdough loaf?

Yes, but not structurally. A deflated loaf may still taste excellent. Slice and toast it, or repurpose into croutons or bread pudding. Focus on fixing the root cause for next time.

Does flour type affect collapse risk?

Absolutely. Low-protein flours (like all-purpose) have less gluten-forming potential. For reliable structure, use bread flour or blend in 20–30% high-protein flour, especially with whole grains.

Checklist: Prevent Sourdough Collapse in 8 Steps

• ✅ Perform autolyse for improved gluten formation
• ✅ Complete 3–4 sets of stretch and folds during bulk fermentation
• ✅ Monitor dough temperature (ideal: 75–78°F / 24–25°C)
• ✅ Use the poke test to determine proofing completion
• ✅ Retard final proof in the fridge for better control
• ✅ Score with a sharp blade at a 30–45° angle
• ✅ Preheat baking vessel for at least 45 minutes
• ✅ Avoid opening the oven during the first 20 minutes

Conclusion: Build Confidence Through Consistency

A collapsing sourdough loaf isn’t a failure—it’s feedback. Each bake teaches you more about your environment, ingredients, and technique. The fixes aren’t mysterious: they’re rooted in understanding dough behavior and respecting the balance between fermentation, structure, and heat.

Start by focusing on one variable at a time—proofing duration, scoring depth, or oven preheat time. Track your changes and results. Soon, you’ll develop the intuition that turns inconsistent results into repeatable success. Your ideal loaf isn’t out of reach; it’s just a few informed adjustments away.

💬 Have a collapse story or breakthrough tip? Share your experience in the comments—your insight could help another baker crack the code.