Why Does My Sourdough Bread Collapse During Baking Troubleshooting Tips

Sourdough bread is a rewarding craft, but few things are more frustrating than watching your carefully nurtured loaf rise beautifully in the oven—only to deflate into a dense, flat mass. A collapsed sourdough can feel like a personal failure, especially after hours of feeding, folding, shaping, and waiting. The truth is, collapse during or just after baking is a common issue with clear, identifiable causes. Understanding these root problems—and knowing how to address them—can transform your baking from unpredictable to consistent.

Unlike commercial yeast breads, sourdough relies on wild fermentation, which introduces variability. This natural process demands attention to detail at every stage: starter strength, dough hydration, fermentation timing, shaping technique, and oven dynamics. When any one of these elements falls out of balance, structural integrity suffers. The good news? Most collapse issues are preventable once you know what to look for.

Understanding Sourdough Structure and Collapse

The structure of a sourdough loaf depends on a delicate interplay between gluten development, gas retention, and heat stability. During bulk fermentation and proofing, carbon dioxide produced by wild yeast inflates air pockets within the gluten network. When baked, this network sets into a stable crumb as the starches gelatinize and proteins coagulate. If the structure fails under heat stress, the loaf collapses.

There are two main types of collapse:

• Mid-bake collapse: The loaf rises dramatically (oven spring), then sinks before the crust fully sets.
• Post-bake collapse: The loaf looks fine when removed from the oven but deflates as it cools.

Both point to insufficient structural support. The most common culprits include overproofing, weak gluten development, excessive hydration, or inadequate oven temperature. Each factor compromises the dough’s ability to withstand expansion and set properly.

“Sourdough doesn’t forgive imbalances. A collapsed loaf is rarely about one mistake—it’s usually a chain reaction starting long before the oven.” — Clara Nguyen, Artisan Baker & Fermentation Educator

Key Causes of Sourdough Collapse and How to Fix Them

1. Overproofing: The Silent Killer of Oven Spring

Overproofing is the leading cause of collapse. When dough ferments too long, the gluten matrix begins to break down, and gas bubbles grow too large and unstable. In the oven, rapid expansion ruptures these fragile walls, and the structure caves in before the crust can harden.

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

Tip: Reduce bulk fermentation or final proof time by 30–60 minutes if your kitchen is warm. Cooler environments slow fermentation; warmer ones accelerate it.

2. Weak Gluten Development

Gluten is the scaffolding that holds your loaf upright. Without sufficient strength, even well-proofed dough will sag. Under-kneading, low-protein flour, or skipping stretch-and-folds during bulk fermentation can all lead to poor gluten formation.

For optimal structure, use bread flour (12–14% protein) instead of all-purpose flour. Perform 3–4 sets of stretch-and-folds during the first two hours of bulk fermentation. These folds align gluten strands and increase dough strength without overworking it.

3. Excessive Hydration

High hydration doughs (above 75%) create open, airy crumb structures—but they’re harder to manage. Too much water dilutes gluten, making it harder for the dough to hold its shape. Beginners often chase artisanal-looking loaves without building the necessary skill to handle wet doughs.

If you're struggling with collapse, reduce hydration to 70–72% until your technique improves. You’ll still get great oven spring and flavor, but with better control.

4. Poor Shaping Technique

Shaping isn’t just about aesthetics—it’s about creating surface tension that helps the loaf retain gas during proofing and baking. A loose or unevenly shaped boule won’t expand evenly and may burst unpredictably, weakening overall structure.

To shape properly: flatten the dough gently, fold edges toward the center, then rotate and tighten by dragging the dough across the counter. The final seam should be sealed tightly underneath. Let the loaf rest seam-side down in a floured banneton for proofing.

5. Inadequate Oven Temperature or Steam

Oven spring—the rapid rise in the first 10–15 minutes of baking—requires intense heat and moisture. If your oven isn’t hot enough (ideally 450–475°F / 230–245°C), the crust forms too slowly, allowing gases to escape before the structure sets.

Steam delays crust formation, giving the dough more time to expand. Without steam, the exterior dries too quickly, restricting growth. Use a Dutch oven or place a tray of boiling water in the oven to trap moisture during the first phase of baking.

Troubleshooting Checklist: Prevent Collapse Before Baking

Use this checklist before loading your loaf into the oven to catch potential issues early:

1. ✅ Is your starter active and peaking? It should double within 4–6 hours of feeding and pass the float test.
2. ✅ Did you develop strong gluten? The dough should pass the windowpane test (stretch a small piece thin enough to see light through without tearing).
3. ✅ Is the dough properly proofed? Passed the finger poke test and has visible bubbles but hasn’t become slack.
4. ✅ Was shaping tight enough? The surface should feel taut, not floppy.
5. ✅ Is your oven preheated for at least 45 minutes? Use an oven thermometer to verify actual temperature.
6. ✅ Are you using a covered vessel or steam method? Essential for proper oven spring.
7. ✅ Is the dough scored correctly? One deep slash (½ inch) allows controlled expansion.

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

Do’s	Don’ts
Use bread flour for stronger gluten development	Use all-purpose flour without adjusting hydration
Perform stretch-and-folds every 30 minutes during bulk fermentation	Skip folds to save time
Proof in a cooler environment (72–75°F) for better control	Leave dough in a hot room (>80°F) unattended for hours
Bake in a preheated Dutch oven for steam and heat retention	Bake on a bare sheet pan without steam
Score the dough deeply and confidently before baking	Make shallow or hesitant cuts that restrict expansion
Let the loaf cool completely (2+ hours) before slicing	Cut into a hot loaf, which can appear collapsed due to steam escape

A Real Example: From Collapse to Consistency

Jessica, a home baker in Portland, spent months battling collapsed loaves. She followed recipes exactly but saw inconsistent results. Her starter bubbled nicely, she used a Dutch oven, and she baked at high heat—yet her bread often pancaked halfway through baking.

After reviewing her process, she realized her final proof was lasting 4 hours at room temperature. Her kitchen ran warm (78°F), accelerating fermentation. The dough looked puffy and passed the poke test loosely, but the internal structure was already weakening.

She adjusted by reducing the final proof to 2.5 hours and placing the banneton in the refrigerator overnight for a cold proof. She also started performing four sets of stretch-and-folds during bulk fermentation. Her next loaf rose evenly, had dramatic oven spring, and held its shape perfectly after cooling. The change wasn’t in ingredients—it was in timing and technique.

Step-by-Step Guide to Baking a Structurally Sound Sourdough Loaf

Follow this timeline to minimize collapse risk:

1. Feed your starter 8–12 hours before mixing – Ensure it peaks just as you begin.
2. Mix dough and autolyse for 30 minutes – Let flour hydrate and gluten start forming.
3. Add starter and salt, mix well – Begin bulk fermentation.
4. Perform 3–4 stretch-and-folds over 2 hours – Every 30 minutes during the first half of bulk fermentation.
5. Complete bulk fermentation in 3–4 hours – Dough should be smooth, domed, and slightly jiggly.
6. Pre-shape, rest 20–30 minutes, then final shape – Create surface tension and place seam-side up in a floured banneton.
7. Final proof: 2–3 hours at room temp or overnight in fridge – Use the poke test to confirm readiness.
8. Preheat oven and Dutch oven for 45 minutes at 475°F – Accuracy matters; use a thermometer.
9. Turn out dough, score deeply, and bake covered for 20 minutes – Trap steam for oven spring.
10. Uncover and bake 20–25 minutes more – Until deep golden brown and internal temp reaches 205–210°F.
11. Cool completely on a wire rack (2+ hours) – Never slice early.

Tip: If your loaf collapses only after cooling, check your internal temperature. Underbaked bread (<205°F) lacks structural integrity and collapses as it cools.

Frequently Asked Questions

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

This typically indicates overproofing or weak gluten. The dough expands rapidly due to trapped gas, but the structure can’t support the expansion. The crust hasn’t set fast enough to hold the shape, so it collapses. Ensure your dough is not overfermented and that you’re using strong flour with proper kneading or folding.

Can I save an overproofed loaf?

Possibly. Gently reshape the dough to rebuild tension and return it to the banneton for a shorter, cooler proof (e.g., 30–60 minutes in the fridge). This won’t fully restore structure, but it can improve results. For future batches, shorten proof time.

Does scoring affect collapse?

Yes. Proper scoring controls where the loaf expands. Without a deep, decisive cut, pressure builds internally and causes random bursting, which can weaken the overall shape. Score with a razor or lame at a 45-degree angle, about ½ inch deep.

Conclusion: Build Confidence Through Precision

A collapsed sourdough loaf isn’t a dead end—it’s feedback. Each failed bake reveals something about your process, from starter health to environmental conditions. By systematically addressing factors like proofing time, gluten strength, and oven setup, you gain mastery over one of baking’s most nuanced challenges.

Success in sourdough comes not from perfection, but from observation, adjustment, and repetition. Track your variables: room temperature, fermentation times, flour type, hydration. Small tweaks yield dramatic improvements. With practice, you’ll learn to read your dough like a seasoned baker—knowing when it’s ready, when it’s pushing too far, and how to guide it to a tall, resilient rise.

💬 Have a collapse story or breakthrough tip? Share your experience in the comments—your insight could help another baker turn frustration into triumph.