Sourdough Troubleshooting · Troubleshooting

Why Is My Sourdough Flat and Spreading? 7 Causes and Fixes

A flat loaf is usually a fermentation or dough-strength issue—not a sign that you cannot bake sourdough. Find the cause and make one change at a time.

By Lifetipme•8 min read•Updated October 2026
Rustic sourdough loaf with a natural score on a pale board
Rustic sourdough loaf with a natural score on a pale board · Lifetipme editorial image
Quick answer

Flat sourdough often comes from over-fermentation, a weak starter, too much water for the flour, insufficient gluten development, or loose shaping.

Start with the pattern, not the blame

A sourdough loaf that spreads can feel like a dramatic failure, but the shape gives you information. If it spreads before baking, the dough may be too wet, weak, or over-fermented. If it rises in the oven but later collapses, the crumb may be underbaked or the structure may not have set.

7 common causes and fixes

1. Bulk fermentation went too farWhy: The dough fermented until gluten strength broke down.Try: Shape earlier next time and use rise plus texture, not the clock alone.
2. Final proof was too longWhy: The shaped dough lost the tension needed to hold its form.Try: Shorten the proof or chill the dough sooner.
3. Starter was weakWhy: The dough did not produce enough gas or strength.Try: Refresh the starter until it doubles predictably before mixing.
4. Hydration was too highWhy: The flour could not absorb enough water for a stable dough.Try: Hold back some water and start around 65–70% hydration.
5. Not enough strength was builtWhy: The dough remained slack after mixing.Try: Add two or three gentle folds early in bulk.
6. Shaping was too looseWhy: The surface had no tension to support the rise.Try: Create a smooth outer skin without tearing the dough.
7. Oven or pan was not hot enoughWhy: The dough spread before it set.Try: Preheat fully and bake on a hot surface with steam if your method uses it.

Read the dough before shaping

A healthy dough should feel elastic and hold a rounded edge when you turn the bowl. If it is very sticky and puddles across the counter, treat that as a warning. You may be late in bulk, working with too much water, or using a flour that needs more strength.

Build strength without tearing

During the first 90 minutes, complete stretch-and-folds or coil folds every 20–30 minutes. Lift enough dough to feel resistance, then fold it over itself. Stop when the dough becomes smoother; excessive handling can remove the gas you are trying to build.

Shape for support

After a short bench rest, gently pre-shape the dough, rest it, then tighten the final shape by dragging it lightly across the unfloured counter. Use flour only where needed. Too much flour prevents the dough from gripping the surface and makes tension difficult to create.

If you are rebuilding your whole process, The Original Sourdough Bread Recipe gives you a simple formula and sequence to repeat while you change one variable at a time.

A simple next-bake plan

  1. 01
    Use an active starter that rises predictably.
  2. 02
    Reduce water by 20 g if your dough was impossible to shape.
  3. 03
    Mark the dough level and stop bulk around a moderate rise.
  4. 04
    Shape with a smooth, taut outer skin.
  5. 05
    Proof until puffy but still resilient.
  6. 06
    Preheat the oven and baking surface thoroughly.

What success looks like

You are looking for a loaf that holds a rounded form before baking, expands at the score, and cools without collapsing. Take notes about flour, room temperature, starter timing, and dough temperature. A small notebook will teach you more than changing five things at once.

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