Why Does My Sourdough Bread Collapse In The Oven Baking Fixes

Sourdough baking is both an art and a science. When everything aligns—fermentation, shaping, scoring, and oven conditions—the result is a beautifully risen loaf with an open crumb and crisp crust. But when your sourdough collapses in the oven, it can feel like all that effort was wasted. This issue, often called “oven collapse” or “post-oven spring deflation,” is frustrating but fixable. The causes are rarely isolated; they stem from a combination of fermentation missteps, structural weaknesses, or thermal inconsistencies. Understanding the root causes and applying precise corrections can transform your results.

Understanding Oven Collapse: What Happens During Baking

When sourdough enters a hot oven, several critical processes occur simultaneously. The initial burst of expansion, known as oven spring, happens due to trapped carbon dioxide expanding and water converting to steam. This phase typically lasts 10–15 minutes and relies on strong gluten structure and active yeast activity. After this window, the dough sets as proteins coagulate and starches gelatinize. If the structure fails before this setting occurs, the loaf collapses.

Oven collapse doesn’t always mean total failure. Sometimes, the bread simply flattens slightly after peaking. Other times, it caves in dramatically down the center. Both indicate underlying issues in one or more stages of the process: fermentation, shaping, proofing, scoring, or baking technique.

Tip: A collapsed loaf isn't always underbaked—often, it's structurally compromised before it even hits the oven.

Common Causes of Sourdough Collapse and How to Fix Them

1. Overproofing: The Silent Loaf Killer

Overproofing is the most frequent cause of oven collapse. When dough ferments too long, the gluten network weakens, and gas bubbles grow too large. In the oven, these overstretched cells rupture instead of expanding uniformly, leading to deflation.

To test for overproofing, perform the fingertip poke test: gently press your finger about half an inch into the dough. If the indentation springs back slowly and leaves a slight dent, it’s ready. If it doesn’t spring back at all, it’s overproofed. If it springs back immediately, it needs more time.

“Overproofed dough has no resilience left. It rises quickly in the oven because there’s nothing holding it together.” — Daniel Leader, author of *Local Breads*

2. Weak Gluten Development

Gluten provides the scaffolding that holds gas during fermentation and baking. Without sufficient strength, the dough cannot support oven spring. Under-mixed or under-developed dough lacks elasticity and tears easily.

Autolyse (resting flour and water before adding starter and salt) helps hydrate the flour and initiate gluten formation. After mixing, use stretch-and-folds during bulk fermentation to build strength gradually. For high-hydration doughs (75%+ hydration), three to four sets of stretch-and-folds spaced 30 minutes apart are usually effective.

3. Poor Scoring Technique

Scoring isn’t just decorative—it controls where the bread expands. Poorly executed cuts can restrict expansion or create weak points that split unevenly. If the score is too shallow, the crust resists expansion and pressure builds internally, causing random blowouts or collapse.

Use a sharp blade (lame or razor) at a 30–45 degree angle, cutting about ½ inch deep. Make decisive, fluid motions. For round loaves (boules), a single deep cross or spiral works well. For batards, a diagonal slash allows controlled expansion.

4. Inadequate Oven Spring Environment

Oven spring thrives on heat, moisture, and space. A cold oven, lack of steam, or overcrowded Dutch oven inhibits proper rise. Steam keeps the surface pliable so the loaf can expand without cracking prematurely.

Preheat your baking vessel (Dutch oven or combo cooker) for at least 45 minutes. Add boiling water to a preheated tray below if not using a covered pot. Avoid opening the oven during the first 20 minutes of baking.

5. Underbaking or Premature Cooling

If the internal structure hasn’t set by the time you remove the bread, residual heat continues cooking the loaf outside the oven—and may cause it to sink. Always check internal temperature: sourdough should reach at least 205°F (96°C). Crust color alone is not a reliable indicator.

Allow the bread to cool completely—minimum 2 hours—before slicing. Cutting too early releases steam and can make the crumb gummy or cause structural collapse.

Tip: Invest in an instant-read thermometer. It’s the most accurate way to confirm doneness and prevent underbaking.

Step-by-Step Guide to Preventing Oven Collapse

Follow this structured approach to minimize the risk of collapse and improve consistency across batches.

1. Start with a healthy starter: Feed your starter 8–12 hours before mixing dough. It should be bubbly, doubled in size, and pass the float test (a spoonful placed in water floats).
2. Autolyse for 30–60 minutes: Mix flour and water only. Let rest to develop gluten naturally.
3. Mix in starter and salt: Combine thoroughly, then begin stretch-and-folds: 4 sets every 30 minutes during the first 2 hours of bulk fermentation.
4. Monitor bulk fermentation: Duration depends on temperature and starter strength. Typically 3–5 hours at 75°F (24°C). Look for ~30% volume increase, bubbles, and jiggly texture.
5. Shape gently but firmly: Pre-shape, rest 20–30 minutes, then final shape with tension. Avoid degassing.
6. Proof properly: Room temp (4–6 hours) or cold (12–18 hours). Use the poke test to determine readiness.
7. Score confidently: Deep, angled cuts with a sharp blade.
8. Bake with steam: Preheat Dutch oven at 450°F (230°C). Bake covered for 20 minutes, uncovered for 20–25 minutes until deeply golden and internal temp reaches 205°F+.
9. Cool completely: On a wire rack. No peeking or slicing early.

Do’s and Don’ts of Sourdough Baking: Quick Reference Table

Do	Don’t
Use a ripe, active starter	Use a sluggish or unfed starter
Preheat your baking vessel thoroughly	Place dough in a cold or insufficiently heated oven
Score deeply and at an angle	Make shallow, hesitant cuts
Let dough cool fully before slicing	Cut into hot bread
Use the poke test to assess proofing	Rely solely on time for proofing decisions
Check internal temperature before removing from oven	Remove bread based only on crust color

Real Example: From Flat Loaf to Perfect Rise

Sarah, a home baker in Portland, struggled for months with collapsing sourdough. Her loaves would rise beautifully in the oven, peak, then deflate halfway through baking. She assumed she needed more bake time, so she extended it—but the bread dried out without solving the collapse.

After tracking her process, she discovered two key issues: her bulk fermentation ran 6 hours instead of 4, and she shaped her dough immediately after mixing without stretch-and-folds. The over-fermented dough had weak gluten, and poor development made it unable to hold gas.

She adjusted her method: shortened bulk fermentation to 4 hours with three sets of stretch-and-folds, began using a thermometer to verify oven temperature, and started scoring deeper. Within two bakes, her loaves achieved consistent oven spring and held their shape. The transformation wasn’t due to new equipment—it was precision in timing and technique.

Essential Checklist for Reliable Results

• ✅ Starter is fed 8–12 hours prior and passes float test
• ✅ Autolyse completed (30–60 min)
• ✅ 3–4 sets of stretch-and-folds performed during bulk fermentation
• ✅ Bulk fermentation stopped at ~30% rise, not maximum puffiness
• ✅ Final proof tested with fingertip poke—dough springs back slowly
• ✅ Dutch oven preheated for 45+ minutes
• ✅ Scored with sharp blade at 30–45° angle, ~½ inch deep
• ✅ Baked covered for 20 min, uncovered until internal temp ≥205°F (96°C)
• ✅ Cooled completely (2+ hours) before slicing

Frequently Asked Questions

Can I rescue an overproofed loaf?

Possibly. Gently reshape the dough to rebuild some tension and return it to a brief second proof (30–60 minutes). This won’t fully recover lost structure but may reduce collapse. Better yet, use severely overproofed dough for crackers or pan-fried focaccia.

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

This indicates the structure couldn’t sustain the expansion. Common culprits include overproofing, weak gluten, or underbaking. The dough expands rapidly during oven spring but lacks the integrity to maintain that rise once gases escape or the crust hardens.

Does hydration level affect collapse?

Absolutely. Higher hydration doughs (80%+) are more prone to spreading and collapsing if underdeveloped or overproofed. They require stronger gluten networks and careful handling. Beginners should start with 70–75% hydration for better manageability.

Final Thoughts: Consistency Over Perfection

Every collapsed loaf teaches something valuable. Sourdough baking rewards observation, patience, and small adjustments. Rather than chasing perfection, focus on consistency: feeding your starter reliably, monitoring fermentation closely, and refining your technique one batch at a time.

The goal isn’t just to avoid collapse—it’s to understand the dialogue between dough, time, and temperature. When you master that balance, your bread won’t just survive the oven; it will thrive in it.

💬 Have you cracked the code on oven collapse? Share your breakthrough moment or favorite tip in the comments—your experience could help another baker finally bake their best loaf.