The most common reason: your dough is overproofed before it goes in
Sourdough that rises well on the counter but stays flat in the oven has usually spent too long fermenting before baking. When dough ferments past its peak, the gluten network weakens and the yeast runs out of food. The dough looks puffy and ready, but it has no strength left to spring up when heat hits it—a problem called oven spring failure.
You can test this by poking the dough gently with a floured finger. If the indent springs back slowly or not at all, the dough is overproofed. If it springs back quickly, it needs more time. The sweet spot is when the indent springs back halfway in a few seconds.
The fix is to shorten your bulk fermentation (the first rise, before shaping) or your final proof (after shaping, before baking). Start by reducing final proof time by 15 to 20 minutes and bake at the same temperature. Watch the dough instead of the clock—it should increase by about 50 percent, not double.
Key Takeaways
- Overproofed dough—left to rise too long before baking—collapses in the oven because the gluten is exhausted and cannot trap steam.
- A poke test tells you if dough is ready: the indent should spring back halfway in a few seconds, not disappear or stay put.
- Cold fermentation in the fridge slows rising and gives you a wider window to catch the dough at the right moment.
- Oven temperature matters: if your oven runs cool, the dough will not spring before the crust sets, and it will stay dense.
- Weak starter or low hydration dough can also prevent rise, but overproofing is the most common culprit.
How to tell if your starter is strong enough
A weak or sluggish starter will not ferment your dough fast enough or produce enough gas to create rise. If your starter takes more than 12 hours to double after feeding, or if it does not smell tangy and active, it is not ready to use.
Before mixing dough, feed your starter and wait until it peaks—when it has risen to its highest point and just begun to fall back. This usually takes 4 to 8 hours at room temperature, depending on how warm your kitchen is. Use the starter at its peak, not hours later when it has collapsed.
If your starter is sluggish, feed it once a day for a week at the same time each day, keeping it at room temperature (68 to 75 degrees Fahrenheit is ideal). A consistent schedule trains the yeast and bacteria to be more active. Once it reliably doubles within 6 to 8 hours, it is strong enough for baking.
Temperature and timing: why cold fermentation helps
Dough ferments faster when it is warm and slower when it is cold. If your kitchen is warm (above 75 degrees), your dough may overproof before you realize it. Cold fermentation—placing shaped dough in the fridge overnight or for 8 to 16 hours—slows the process and gives you a much wider window to catch the dough at the right moment.
Cold dough also develops more flavor and is easier to score because it is stiff. Bake it straight from the fridge without letting it come to room temperature first. The dough will spring more in the oven because it is still cold when the heat hits it.
If you bulk ferment at room temperature, aim for 4 to 6 hours depending on how warm your kitchen is. Poke the dough every hour after the 3-hour mark to watch for the right level of rise. If your kitchen is very warm, reduce bulk fermentation to 3 to 4 hours.
Oven temperature and steam: why they matter for spring
Sourdough needs high heat and steam to rise properly in the oven. If your oven temperature is too low or you are not creating steam, the crust will set before the dough has a chance to spring.
Most sourdough recipes call for baking at 450 to 500 degrees Fahrenheit. If your oven runs cool (many home ovens do), the actual temperature inside may be 25 to 50 degrees lower than the dial shows. Buy an oven thermometer and place it on the rack where you bake. If the reading is lower than the setting, adjust your dial upward or bake longer.
Steam is equally important. For the first 20 minutes of baking, the dough needs humid heat to stay soft so it can expand. You can create steam by placing a hot Dutch oven over the dough, spraying the oven walls with water before loading the dough, or placing a pan of boiling water on the bottom rack. Without steam, the crust hardens too fast and the dough cannot rise.
Hydration and gluten strength: when dough is too wet or too weak
Dough that is too wet (high hydration) can be hard to handle and may not hold its shape well enough to trap gas and rise. If your dough spreads flat instead of puffing up, it may be too loose.
Start by reducing hydration by 2 to 3 percent—if your recipe calls for 80 percent hydration (80 grams water per 100 grams flour), try 77 or 78 percent instead. A stiffer dough is easier to shape and holds its structure better in the oven. You can always add water back if the dough feels too dry to work with.
Weak gluten development also prevents rise. Make sure you are stretching and folding the dough during bulk fermentation—do this every 30 minutes for the first 2 hours. This builds strength without kneading. If you skip this step, the dough will not have enough structure to trap gas and rise.
Salt and fermentation speed: how much matters
Salt slows fermentation by controlling yeast activity. Too much salt will slow your dough so much that it barely rises. Too little salt allows fermentation to run away and overproof quickly.
Standard sourdough uses about 2 percent salt by weight of flour (2 grams per 100 grams flour). If your recipe calls for more than 2.5 percent, try reducing it slightly. If you are using less than 1.5 percent, increase it a little. Small changes make a big difference in how fast your dough ferments.
Add salt after the initial mix, not at the very beginning. Mixing salt directly with the starter can slow it down. Wait 30 minutes after mixing flour and water, then add salt and mix it in thoroughly.
Scoring and shaping: why they affect oven spring
A dull blade or shallow score will not open properly in the oven, and the dough will bulge out the sides instead of rising up. Use a sharp lame (a razor blade on a stick) or a clean razor blade, and score at a 30 to 45 degree angle about half an inch deep.
Shaping also matters. If you shape too loosely, the dough will spread instead of rise. If you shape too tightly, you will trap air and the dough may burst unevenly. Shape firmly but not aggressively—the dough should feel taut on the outside but not rock-hard.
Place shaped dough seam-side up in a floured banneton (proofing basket) or bowl lined with a towel. This supports the dough and helps it rise upward instead of spreading outward.
Frequently Asked Questions
Can I fix overproofed dough before baking?
If you catch it early—the indent from the poke test springs back halfway—you can still bake it, but reduce oven time by 5 to 10 minutes because it will brown faster. If the dough is fully collapsed and does not spring back at all, it is too far gone. Start over with a shorter proof next time.
What if my dough rises on the counter but not in the oven?
This almost always means overproofing. The dough looks ready because it has risen, but the gluten is exhausted. Shorten your final proof by 15 to 20 minutes, or move to cold fermentation so you can control timing better. Also check your oven temperature with a thermometer.
Does the room temperature affect how long to proof?
Yes, significantly. Warm kitchens (above 75 degrees) speed fermentation by hours. Cool kitchens (below 65 degrees) slow it down. If your kitchen varies, use the poke test instead of timing—it is more reliable than the clock.
Should I let cold dough come to room temperature before baking?
No. Bake cold dough straight from the fridge. It will spring more in the oven because the cold slows the yeast just enough that it is still active when the heat hits. Letting it warm up first can lead to overproofing while you wait.
How do I know if my starter is the problem?
Feed your starter and watch it. It should double in size within 6 to 8 hours at room temperature and smell tangy and active. If it takes longer or does not rise much, feed it daily at the same time for a week. A weak starter is fixable, but it takes consistency.