✔ Updated · 9 causes + fixes, with temps and times
Flat sourdough is heartbreaking after a day of babysitting dough. I've baked my share of frisbees, and the fix is usually one of these nine things.
Sourdough usually doesn't rise because the starter is weak or used past its peak, the dough is too cold, or bulk fermentation was cut short. Use a starter that doubles within 4 to 8 hours of feeding, keep the dough around 75 to 78°F, and let it bulk ferment until it has risen 50 to 75%, which can take 4 to 12 hours.
- Check the starter: bubbly, domed, doubled after feeding.
- Keep it warm: dough at 75 to 78°F.
- Be patient: bulk ends at a 50 to 75% rise, not a clock time.
- Build strength: 3 to 4 sets of stretch and folds.
Quick Diagnosis
| What you see | Most likely cause | Fix |
|---|---|---|
| No rise at all after 6+ hours | Weak starter or very cold dough | Revive the starter; ferment at 75 to 78°F |
| Slow, small rise | Cool kitchen or short bulk | Give it more time somewhere warm |
| Rises but spreads flat | Weak gluten or loose shaping | More stretch and folds, tighter shaping |
| Rose, then collapsed | Overproofed | Shorter proof or a cold proof |
| Dense, gummy loaf | Underproofed | Longer bulk, check with the poke test |
1. Your Starter Is Weak or Past Its Peak
This is the big one. A healthy starter should at least double within 4 to 8 hours of feeding at room temperature, look domed and bubbly, and smell pleasantly tangy. If it barely moves, or you used it hours after it peaked and collapsed, there just isn't enough yeast power to lift the loaf.
- Feed it on a regular schedule (I do 1:1:1 starter, flour, water by weight) for a few days until it doubles reliably.
- Use it at or just before its peak, when it's domed and full of bubbles.
- A new starter often needs 1 to 2 weeks before it can raise a loaf.
2. Your Kitchen or Dough Is Too Cold
Wild yeast is slow at the best of times, and cold makes it crawl. Dough that sits at 65°F can take twice as long as dough at 76°F, and it can look like nothing is happening for hours.
- Aim for a dough temperature of about 75 to 78°F; use warm water (around 80 to 85°F) when mixing in winter.
- Ferment in the oven with only the light on, or in a cooler with a jug of warm water.
3. You Cut the Bulk Fermentation Short
Recipes give times, but the dough sets the schedule. At 75 to 78°F, bulk fermentation usually takes 4 to 6 hours; in a cool kitchen it can take 8 to 12.
- Watch the dough, not the clock: look for a 50 to 75% rise, a domed, jiggly surface and bubbles on the sides and top.
- Use a straight-sided container and mark the starting level so you can see the rise.
4. The Gluten Is Underdeveloped
Gluten is the net that traps gas. Without enough strength, the bubbles escape and the dough spreads instead of rising up.
- Do 3 to 4 sets of stretch and folds, 30 minutes apart, in the first 2 hours of bulk.
- Look for a smooth, stretchy dough that holds its shape better with each set.
5. Too Much Salt
Salt tightens gluten and slows fermentation, which is good in the right amount. Too much and your starter struggles.
- Use about 2% of the flour weight: 10 g salt for 500 g flour.
- Weigh it; teaspoons vary a lot between salt brands and crystal sizes.
6. Your Flour Is Too Weak
All-purpose flour with lower protein makes a softer, flatter loaf. Very fresh whole wheat or rye needs more water and ferments faster, which can catch you out.
- Use bread flour (about 12 to 13% protein) for a lofty loaf.
- When adding whole grain, start at 20 to 30% of the flour and add a little extra water.
7. The Hydration Is Off
Very stiff dough rises slowly and stays tight; very wet dough can be hard to build strength in and spreads flat.
- If you're starting out, try 65 to 70% hydration (325 to 350 g water per 500 g flour) before moving to wetter doughs.
8. It Overproofed
Sometimes the dough did rise, then collapsed. Overproofed dough looks slack and bubbly, smells boozy and deflates when touched, so it bakes flat.
- Do the poke test before baking: a floured finger dent should spring back slowly and leave a slight dimple. If it doesn't spring back at all, it's overproofed.
- Use a cold proof in the fridge (8 to 16 hours) for more control.
9. Add-Ins or Water Are Slowing the Yeast
Butter, oil, sugar, honey, cinnamon and dried fruit all slow fermentation. Heavily chlorinated tap water can also make a starter sluggish.
- Expect enriched sourdough to take longer, and add inclusions during the last folds.
- If your starter struggles, try filtered water or tap water left out for a few hours.
How to Fix Sourdough That Did Not Rise
- Move it somewhere warm (75 to 80°F) and give it 2 to 4 more hours. Often that's all it needs.
- If nothing happens, knead in a fresh, active portion of starter (about 50 g), or 1/2 teaspoon instant yeast dissolved in a splash of water, then let it rise again.
- Out of time? Roll it thin for flatbread, crackers or pizza instead of baking a dense loaf.
My Sourdough Notes
My early loaves were frisbees, and almost every time it was a starter I used too early or a cold kitchen in winter. A cheap thermometer in the dough fixed more of my bakes than any new technique.
More help: can you bake dough that hasn’t risen, why sourdough won’t hold its shape, why your dough isn’t rising and artisan vs sourdough bread.
Frequently Asked Questions
Why is my sourdough not rising?
The most common reasons are a weak or past-peak starter, a cold kitchen, and not enough bulk fermentation time. Less often it's too much salt, weak flour, low gluten strength or overproofing. Check the starter first: it should double within 4 to 8 hours of feeding.
How long should sourdough take to rise?
Bulk fermentation usually takes 4 to 6 hours at 75 to 78°F and 8 to 12 hours in a cool kitchen. The final proof is 1 to 3 hours at room temperature or 8 to 16 hours in the fridge. Judge by the dough's look and feel, not the clock.
Can I still bake sourdough that didn't rise?
You can, and it's safe, but it will be dense and gummy. It's better to give it more time somewhere warm or knead in fresh starter and let it rise again. If you're out of time, roll it out for flatbread or pizza instead.
Why is my levain not rising?
A levain that won't rise is usually too cold, fed with too much flour for the amount of starter, or made from a starter that wasn't active yet. Keep it at about 75 to 80°F, use a ripe starter, and give it time to double before mixing.
Does sourdough need to double in size?
Not usually during bulk fermentation. Most bakers aim for a 50 to 75% rise, with a domed, jiggly surface and visible bubbles. Letting it fully double at warm temperatures can lead to overproofing and a flat loaf.
