How to fix a gummy sourdough crumb

A gummy sourdough crumb usually means the loaf was underbaked or cut too warm. Bake until the internal temperature hits 96-99C (205-210F), then let it cool for at least 2 hours before slicing. The other common causes are underfermentation and hydration that runs higher than your flour can hold. Each one has a clear fix.

Check the bake first

Most gummy crumb is just heat and time. The center of a sourdough loaf needs to reach 96-99C (205-210F) for the starches to set. A loaf that looks dark on the outside can still be wet in the middle, especially in a larger boule.

• Use an instant-read probe pushed into the center through the base or a side.
• If you keep landing short, add 5-10 minutes with the lid off and watch the color.
• Steam-heavy bakes (Dutch oven) can brown fast while the core lags, so trust the probe over the crust color.

These are estimates. Ovens vary, and a 900g loaf needs longer than a 600g one. Judge by the reading and the feel of the crust, which should sound hollow when tapped.

Let it cool all the way

Cutting a hot loaf is the fastest way to make a fine crumb look gummy. The interior is still cooking and setting as it cools, and the trapped steam needs to leave. Slice early and you smear the moist starch into a paste.

Cool on a wire rack, not on a board or in the pan. Give it 2 hours minimum for a standard loaf, longer for anything dense or high-hydration. If you only fix one thing, fix this.

Rule out underfermentation

If the bake and cool are right and the crumb is still tight and damp, fermentation is the next suspect. Underfermented dough has not built enough structure or eaten enough of the flour, so it stays heavy and wet inside.

Signs to look for:

• Little to no rise during bulk, maybe 30-50% instead of doubling.
• A dense, closed crumb with few holes.
• A pale, flat loaf with weak oven spring.

Push the bulk longer and warmer. Dough at 24-26C (75-79F) ferments noticeably faster than at 20C (68F). A healthy starter helps here, so confirm yours is active before you blame the schedule. See feeding your starter if the rise is sluggish.

Bring the hydration down

Water you cannot manage shows up as a wet, sticky interior even when everything else is on point. High hydration is great once your technique and flour can carry it, but it punishes you early on.

Flour type	Comfortable starting hydration
Supermarket bread flour	65-70%
Strong bread flour	70-75%
Whole wheat or rye blend	60-68%

Drop your total water by 5% and bake again. If the crumb tightens up and the gum disappears, you found it. Run the numbers with [/calculators/hydration] so you are changing one variable, not guessing.

A quick checklist

When a gummy sourdough crumb shows up, work through these in order:

1. Probe the center: 96-99C (205-210F) or keep baking.
2. Cool fully on a rack, 2 hours or more.
3. Check bulk rise and starter activity for underfermentation.
4. Lower hydration by 5% if the dough handled wet.

Change one thing per bake. Stack three fixes at once and you will not know which one worked. Most bakers find the problem is the cut or the bake, so start there before you touch the recipe.