Why Is My Sourdough Bread Gummy Inside Baking Mistakes To Avoid

There’s nothing more disappointing than slicing into a loaf of sourdough you’ve nurtured for days—only to find a dense, sticky, gummy interior instead of the open, springy crumb you hoped for. A gummy texture isn’t just unappetizing; it often signals one or more preventable errors in your sourdough process. While sourdough baking is both an art and a science, understanding where things go wrong can transform your results. From underproofing to improper hydration, several common missteps lead to that dreaded gumminess. This guide breaks down the root causes, offers actionable solutions, and equips you with the knowledge to consistently bake light, flavorful sourdough with a perfect crumb structure.

Understanding Gummy Sourdough: What It Really Means

When bakers describe their sourdough as “gummy,” they’re usually referring to a wet, sticky, undercooked-feeling interior—even when the crust appears golden and crisp. The crumb may look pale, lack oven spring, and stick to the knife when sliced. This texture occurs when starches haven’t fully gelatinized, gluten hasn’t developed properly, or moisture remains trapped inside due to incomplete baking or poor fermentation.

Gumminess is not the same as chewiness. A well-baked sourdough should be pleasantly elastic and moist, but not gluey or pasty. The difference lies in proper fermentation, gluten development, and adequate heat exposure during baking. If your bread tastes raw or leaves a starchy film on your teeth, it’s likely underbaked or underfermented.

Tip: Always let your sourdough cool completely—ideally 2–3 hours—before slicing. Cutting too early traps steam, which can make the crumb seem gummy even if it’s fully baked.

Common Baking Mistakes That Cause Gummy Crumb

The journey from flour and water to a flawless loaf involves precise timing, temperature control, and technique. Even small deviations can result in a gummy interior. Below are the most frequent culprits behind this frustrating outcome.

1. Underproofing the Dough

Underproofing is the leading cause of gummy sourdough. When dough doesn’t ferment long enough, the yeast and bacteria in your starter don’t produce sufficient gas or organic acids to create an open crumb. The result is a tight, dense structure that retains moisture and bakes unevenly.

You can spot underproofed dough by its resistance to movement. It won’t jiggle like jelly when nudged, and it may deflate quickly when scored. Properly proofed dough should feel airy, wobble slightly, and slowly regain shape after a gentle poke.

2. Overhydration Without Proper Gluten Development

High hydration (above 75%) creates a more open crumb but demands strong gluten structure. If your flour lacks strength (e.g., low-protein all-purpose flour) or you skip sufficient kneading/folding, excess water won’t be absorbed and will remain free in the dough. During baking, this water turns to steam but can’t escape efficiently, leading to a sticky interior.

Using high-protein bread flour and performing regular stretch-and-folds during bulk fermentation helps build the necessary strength to hold moisture without collapsing.

3. Inadequate Oven Spring Due to Poor Scoring

If your loaf doesn’t expand properly in the oven (known as oven spring), internal pressure builds up, preventing steam from escaping. This trapped moisture contributes to gumminess. Shallow or improperly angled cuts restrict expansion, forcing the dough to burst unpredictably and bake unevenly.

Score deeply—at least ½ inch—and use a sharp blade at a 30-degree angle to allow controlled expansion. Practice consistent scoring patterns to promote even rise.

4. Baking at Too Low a Temperature or for Too Short a Time

Sourdough needs intense heat to set the crust quickly and drive out internal moisture. Baking at temperatures below 425°F (220°C) or removing the bread too soon prevents full starch gelatinization and evaporation of excess water.

The internal temperature of a fully baked sourdough should reach 205–210°F (96–99°C). Use an instant-read thermometer to verify doneness. If it reads below 200°F, return it to the oven, even if the crust looks done.

5. Skipping Steam or Using It Incorrectly

Steam in the first 15–20 minutes of baking keeps the crust flexible, allowing maximum oven spring. However, failing to vent steam afterward traps moisture inside the loaf. Leaving the lid on a Dutch oven too long or baking in a sealed environment without ventilation leads to condensation, which reabsorbs into the crumb.

Always remove the lid or release steam after the initial phase to ensure the crust dries and sets properly.

Baking Process Checklist: Avoid Gumminess Step by Step

To ensure your sourdough turns out light and airy, follow this checklist throughout the baking process:

• ✅ Use a mature, active starter that doubles within 4–6 hours of feeding
• ✅ Perform 3–4 sets of stretch-and-folds during bulk fermentation to build strength
• ✅ Ferment at 75–78°F (24–26°C) for optimal yeast activity
• ✅ Proof until the dough jiggles like jelly and passes the poke test (slow rebound)
• ✅ Preheat your Dutch oven or baking stone for at least 45 minutes at 450°F (230°C)
• ✅ Score deeply with a razor blade at a shallow angle
• ✅ Bake covered for 20 minutes to trap steam, then uncover and bake 20–25 minutes more
• ✅ Check internal temperature—must reach at least 205°F (96°C)
• ✅ Cool completely on a wire rack before slicing

Do’s and Don’ts: Hydration and Flour Choices

Action	Do	Don't
Flour Selection	Use high-protein bread flour (12–14% protein) or blend with whole wheat for strength	Avoid low-protein all-purpose flour for high-hydration recipes
Hydration Level	Start with 70–75% hydration if you're still mastering technique	Don’t jump to 80%+ hydration without building dough-handling skills
Water Temperature	Use lukewarm water (75–80°F) to support fermentation	Don’t use cold water in a cool kitchen—it slows fermentation and risks underproofing
Starter Maturity	Add starter at peak ripeness—just after it reaches maximum volume	Don’t use starter straight from the fridge or before it’s bubbly and active

Real Example: How One Baker Fixed Her Gummy Loaves

Sarah, a home baker in Portland, struggled for months with dense, gummy sourdough despite following online recipes closely. Her loaves looked promising in photos—golden crust, decent rise—but always turned out sticky inside. She experimented with different flours and hydration levels but saw no improvement.

After tracking her process, she realized two critical issues: she was proofing her dough for only 8 hours at room temperature, and she was cutting the bread within 30 minutes of pulling it from the oven. By extending her bulk fermentation to 10 hours and refrigerating the shaped loaf overnight (retarding), she achieved better flavor and structure. She also began using a thermometer to check internal temperature and waited three full hours before slicing.

Her next loaf had an open crumb, crisp crust, and no gumminess. “I couldn’t believe how much difference patience made,” she said. “I was rushing the cooling, and my dough wasn’t fermenting long enough.”

Expert Insight: What Professionals Emphasize

“Time and temperature are the silent architects of sourdough success. Most gummy loaves come from impatience—not giving the dough enough time to develop structure or the bread enough time to cool. Fermentation isn’t a race.” — Miguel Ruiz, Artisan Baker and Sourdough Instructor at The Bread Lab Academy

“The number one mistake I see? People trust the clock instead of the dough. Your kitchen, flour, and starter are unique. Learn to read the signs: jiggle, puffiness, and slow spring-back tell you more than any timer.” — Lena Park, Founder of Wild Rise Bakery

Step-by-Step Guide to Prevent Gummy Sourdough

Follow this detailed sequence to maximize your chances of achieving a well-baked, non-gummy loaf:

1. Feed your starter 8–12 hours before mixing: Ensure it’s active and doubled in size. Discard and feed with equal parts flour and water.
2. Mix dough with proper hydration: For beginners, aim for 70–75%. Use bread flour for better gluten formation.
3. Bulk ferment at 75–78°F: Perform 3–4 sets of stretch-and-folds over 2–3 hours. Let rest until puffy and ~50% increased in volume.
4. Shape and proof properly: After bulk, pre-shape, rest 20 mins, then final shape. Proof at room temp for 2–4 hours or refrigerate overnight (cold proof enhances flavor and control).
5. Preheat oven and vessel: Heat Dutch oven or baking steel at 450°F for 45+ minutes.
6. Score and bake: Transfer dough to vessel, score deeply, cover, and bake 20 min. Uncover, reduce heat to 425°F, bake 20–25 min more.
7. Check internal temperature: Insert thermometer into center. Must read 205–210°F.
8. Cool completely: Wait at least 2–3 hours on a wire rack. Slicing too early = trapped steam = gummy crumb.

Frequently Asked Questions

Can I fix a gummy loaf after baking?

No, once cooled, a gummy loaf cannot be salvaged. However, you can repurpose it—toast thick slices, make breadcrumbs, or use in strata. To prevent recurrence, adjust fermentation time, baking duration, or cooling period.

Does whole wheat sourdough always turn out denser?

Whole wheat flour absorbs more water and has less gluten-forming protein, so it tends to yield a denser crumb. But with proper hydration (up to 80%), longer autolyse, and blending with bread flour, you can achieve a lighter texture. Just expect less openness than white sourdough.

Why does my bread taste sour and gummy?

Excessive sourness combined with gumminess often points to overfermentation. While sour flavor comes from lactic acid, overproofing weakens gluten and produces excess acidity, which interferes with starch setting. Stick to recommended proof times and monitor dough behavior, not just clock time.

Final Tips for Consistently Great Sourdough

Tip: Keep a baking journal. Record starter activity, room temperature, fermentation times, and outcomes. Patterns will emerge, helping you refine your process.

Tip: Invest in an instant-read thermometer. It removes guesswork and ensures your bread is truly done inside.

Tip: If you live in a humid climate, reduce hydration by 5%—flour absorbs moisture differently depending on environment.

Conclusion: Turn Mistakes Into Mastery

Gummy sourdough doesn’t mean you’ve failed—it means you’re learning. Every baker encounters this issue at some point. The key is identifying the root cause, whether it’s underproofing, poor gluten development, or premature slicing. With attention to detail, consistency in process, and respect for fermentation timelines, you’ll soon bake loaves with a tender, airy crumb and satisfying chew.

Don’t rush the rise. Don’t cut too soon. And don’t give up after one imperfect loaf. Sourdough rewards patience and observation. Apply these insights, track your progress, and celebrate each improvement. Your perfect loaf is closer than you think.

💬 Have a sourdough success story or a persistent challenge? Share your experience in the comments—your insight could help another baker overcome the gummy bread hurdle!