Why Is My Sourdough Bread Gummy Inside Baking Mistakes And How To Fix Them

Sourdough bread should have a crisp crust, an open crumb, and a satisfying chew—not a dense, sticky, or gummy interior. Yet many home bakers, even experienced ones, find themselves slicing into a loaf only to discover a wet, gluey texture that clings to the knife. This issue isn’t just disappointing—it’s avoidable. The gummy crumb in sourdough typically stems from one or more preventable mistakes during fermentation, shaping, proofing, or baking. Understanding these root causes allows you to diagnose the problem and make precise adjustments for better results.

The journey from flour and water to a beautifully risen, well-textured loaf involves a delicate balance of time, temperature, hydration, and technique. When any part of this system falls out of alignment, the result can be underdeveloped structure, trapped moisture, or incomplete starch gelatinization—each leading to gumminess. Below, we break down the most common culprits and provide actionable fixes so you can bake consistently excellent sourdough.

Underproofing: The Most Common Cause of Gummy Crumb

Underproofing occurs when dough hasn’t fermented long enough to develop sufficient gas and structural strength. A dough that goes into the oven too early collapses slightly during baking, trapping moisture and preventing full oven spring. The result? A dense, compact crumb with a sticky, gummy texture.

To determine if your dough is properly proofed, use the \"finger poke test\": gently press your fingertip about half an inch into the dough. If it springs back slowly and leaves a slight indentation, it's ready. If it springs back quickly, it needs more time. If it doesn’t spring back at all and feels like pudding, it’s overproofed.

Temperature plays a major role in proofing time. Cold kitchens slow fermentation dramatically. If you're proofing at room temperature (around 68°F / 20°C), expect bulk fermentation to take 4–6 hours and final proof 3–4 hours. Warmer environments (75–78°F / 24–26°C) can cut those times significantly.

Tip: Use a clear plastic container to monitor dough rise—look for a 30–50% increase in volume during bulk fermentation and a similar expansion during final proof.

Inadequate Oven Spring and Low Baking Temperature

Oven spring—the rapid expansion of dough in the first 15 minutes of baking—is critical for developing an open crumb and driving off excess moisture. If your oven isn’t hot enough or lacks steam, the crust sets too quickly, stifling expansion and sealing in water that turns into gumminess.

Most sourdough recipes require a preheated oven at 450–475°F (230–245°C). Baking at lower temperatures prevents proper starch gelatinization and protein coagulation, both essential for structure. Additionally, without steam, the surface dries too fast, limiting expansion.

To improve oven spring:

• Preheat your Dutch oven or baking stone for at least 45 minutes.
• Create steam by placing a metal tray with lava rocks in the oven and pouring hot water into it just before loading the dough.
• Score your loaf deeply (½ inch) to allow controlled expansion.

“Steam in the first phase of baking keeps the crust flexible, allowing maximum oven spring. Without it, you’re essentially baking with the handbrake on.” — Daniel Leader, author of *Local Breads*

Overhydration Without Proper Gluten Development

High-hydration doughs (above 75%) are popular for their open crumb, but they demand strong gluten structure. If your dough is too wet for your flour type or mixing method, the gluten network may not support the gas bubbles, causing collapse and moisture pooling in the center.

All-purpose flour absorbs less water than bread flour and has lower protein content, making it harder to build strength in wet doughs. Similarly, under-kneaded or poorly developed dough won’t hold its shape, leading to poor gas retention and uneven baking.

To manage hydration:

1. Start with a moderate hydration (70–75%) if you're still mastering technique.
2. Use high-protein bread flour or add 5–10% vital wheat gluten to all-purpose flour.
3. Perform regular stretch and folds during bulk fermentation (every 30 minutes for the first 2 hours).
4. Check for windowpane development: stretch a small piece of dough thin enough to see light through without tearing.

Baking Time and Cooling: The Hidden Factors

Even with perfect fermentation and oven spring, underbaking leads directly to gumminess. Sourdough needs sufficient time in the oven for the internal structure to set and excess moisture to evaporate. Pulling the loaf out too soon traps steam inside, which condenses as it cools, creating a gummy core.

A properly baked sourdough loaf should reach an internal temperature of 208–210°F (98–99°C). At this point, starches are fully gelatinized, and proteins are set. Use an instant-read thermometer to verify doneness—don’t rely solely on color or tapping the bottom.

Equally important is cooling. Never slice into a hot loaf. Cutting too early releases trapped steam and collapses the crumb, resulting in stickiness. Allow bread to cool completely—ideally 2–3 hours—on a wire rack to let moisture redistribute evenly.

Tip: If your loaf smells alcoholic or tastes sour beyond tanginess, it may be overfermented—adjust proofing time or temperature next time.

Common Mistakes and How to Fix Them: A Comparison Table

Mistake	Effect on Bread	Solution
Underproofing	Dense, gummy crumb; poor oven spring	Extend bulk and final proof; use finger poke test
Low oven temperature	Pale crust; underbaked center	Preheat to 450°F+; use oven thermometer
No steam during baking	Thick, tough crust; limited rise	Add steam with Dutch oven or tray method
Overhydrated dough	Collapses easily; sticky, wet crumb	Reduce water; strengthen gluten with folds
Slicing while warm	Gummy texture; collapsed structure	Cool completely before cutting (2–3 hours)
Insufficient gluten development	Flat loaf; poor gas retention	Perform stretch and folds; check windowpane

Step-by-Step Guide to Avoiding Gummy Sourdough

Follow this timeline to ensure each stage supports a light, non-gummy crumb:

1. Feed your starter 6–12 hours before mixing – Use it when it’s at peak activity (just after doubling, with visible bubbles).
2. Mix dough and autolyse for 30 minutes – Let flour hydrate before adding salt and starter to improve gluten formation.
3. Bulk ferment at 75–78°F (24–26°C) for 4–5 hours – Perform 4 sets of stretch and folds in the first 2 hours.
4. Shape tightly and place in a well-floured banneton – Pre-shape first if needed for tension.
5. Final proof for 3–4 hours at room temp or overnight in fridge – Cold proof enhances flavor and makes scoring easier.
6. Preheat oven and vessel to 475°F (245°C) for 45 minutes – Use an oven thermometer to verify accuracy.
7. Bake covered for 20 minutes, then uncovered for 25–30 minutes – Until deep golden brown and internal temp reaches 208–210°F.
8. Cool completely on a wire rack – Wait at least 2 hours before slicing.

Mini Case Study: From Gummy Loaf to Bakery-Quality Results

Sarah, a home baker in Portland, had been struggling with gummy sourdough for months. Her loaves looked promising—great rise, nice color—but always turned out sticky inside. She followed recipes closely but didn’t track temperature or use a thermometer.

After reviewing her process, she realized three issues: her kitchen was only 65°F, causing underproofing; she was baking at 425°F instead of 475°F; and she was slicing within 45 minutes of pulling the loaf from the oven.

She adjusted by moving her dough to a warmer spot near the oven, increasing baking temperature, and waiting 3 hours before cutting. On her next attempt, the crumb was airy and dry, with no trace of gumminess. “I couldn’t believe the difference,” she said. “It wasn’t the recipe—it was the details I ignored.”

Frequently Asked Questions

Can I fix a gummy loaf after baking?

No—once the bread is cooled with a gummy crumb, the structure and moisture distribution are already compromised. However, you can repurpose it: toast thick slices, make breadcrumbs, or use it in strata or bread pudding.

Does using whole grain flour cause gumminess?

Whole wheat, rye, or other whole grain flours absorb more water and contain bran that cuts gluten strands, which can lead to denser, moister crumb if not handled correctly. To avoid gumminess, increase hydration slightly, extend autolyse, and consider blending with white flour (e.g., 20–30% whole grain).

Why does my sourdough taste sour and gummy?

Excessive sourness combined with gumminess often points to overfermentation. Extended fermentation breaks down starches and weakens gluten, leading to poor structure and higher acidity. Try shortening bulk fermentation or refrigerating the dough earlier to slow yeast activity.

Essential Checklist for Gummy-Free Sourdough

• ✅ Starter is active and peaking when used
• ✅ Dough passes the finger poke test (slow rebound)
• ✅ Oven and baking vessel preheated to 475°F (245°C)
• ✅ Steam used during first 20 minutes of baking
• ✅ Internal temperature reaches 208–210°F (98–99°C)
• ✅ Loaf cooled completely before slicing (minimum 2 hours)
• ✅ Hydration level matches your flour and skill level
• ✅ Gluten development confirmed via windowpane test

Conclusion: Master the Details, Transform Your Bread

Gummy sourdough isn’t a lost cause—it’s a signal. It tells you where your process needs refinement. Whether it’s proofing time, oven temperature, or patience during cooling, each factor plays a role in achieving that ideal balance of chew, airiness, and dry crumb. Baking sourdough is as much science as art, and the best results come from attentive observation and small, deliberate adjustments.

You don’t need fancy equipment or years of experience to bake great bread. You need consistency, measurement, and the willingness to learn from each loaf. Start tracking your variables: time, temperature, flour type, hydration. Over time, patterns will emerge, and so will perfectly textured sourdough.

💬 Have a sourdough success story or a persistent issue? Share your experience in the comments—your insight could help another baker crack the code to gummy-free bread!