Why Your Sourdough Isn't Rising—and How to Fix It
Sourdough is a conversation between you and biology. When it goes wrong, it's usually because the timing is off, not because you're doing anything fundamentally broken. The good news: once you learn what to look for, you can diagnose almost any problem in real time and correct it.
You need a baseline to troubleshoot
Before you try to fix anything, know what your current starter looks like, what your kitchen temperature is, and roughly how long your bulk fermentation is taking. Write these down for your next bake. Troubleshooting sourdough without a baseline is like trying to fix an engine without knowing what it sounded like before.
- Instant-read thermometer
- Kitchen scale
- Bowl (for proofing)
- Dutch oven or covered baking vessel
- Bench scraper
- Banneton or bowl lined with a towel
Look for the three weak links
Problems almost never come from one thing. Dense crumb usually means weak gluten structure (from a struggling starter or underfermented dough). Poor rise means your dough ran out of gas before it went into the oven—either the starter was weak or fermentation was too slow. Flat loaves are usually a shaping issue or overproofing. Start by checking your starter's strength, then your fermentation timeline, then your technique. Fix them in that order.
The method.
Check your starter
Your starter should roughly double in height within 4–8 hours of feeding, and it should smell pleasantly sour and yeasty, not vinegary or boozy. If it's taking longer than 8 hours or barely rising, it's hungry or cold. Feed it at room temperature (68–72°F) and wait. A weak starter is the root cause of most sourdough failures. If your kitchen is cold, place the jar in a warmer spot—the back of the fridge, next to a heater, or in a proofing box. Don't use it until it's reliably doubling within 4–6 hours.
Measure your dough temperature during bulk fermentation
Get an instant-read thermometer and check your dough's internal temperature 30 minutes after mixing. It should be between 75–78°F. If it's below 72°F, fermentation will crawl, and you'll think nothing is happening. Warm your mixing water slightly (around 85–90°F) to bump the dough temperature up. If your kitchen is cold, cover the bowl loosely with plastic or place it in a turned-off oven with the light on. Cold dough ferments slowly but still ferments—you just won't see obvious bubbles until much later.
Watch the dough, not the clock
Bulk fermentation should take 4–6 hours at 75–78°F. You'll know it's ready when the dough has increased in volume by about 50–75% (not doubled—that's overfermented), the surface looks slightly domed, and you can see a few bubbles just under the surface. If you're relying purely on time and not looking at the dough, you'll miss the window. Poke the dough gently with a floured finger; if the indent springs back slowly (over a few seconds), it's ready. If it springs back immediately, it needs more time. If it doesn't spring back at all, you've gone too far.
Pre-shape and rest
After bulk fermentation, turn the dough out onto a lightly floured surface and gently pre-shape it into a round. Let it rest uncovered for 20–30 minutes. This is called the bench rest. It allows the gluten to relax and gives you a chance to see how the dough is behaving. If it's spreading flat and loose during this rest, your bulk fermentation might have been too long. If it's staying tight and elastic, you're on track.
Shape with intention
Final shaping is where tension matters. Flip the dough seam-side up. Fold the bottom third up and press it into the dough. Fold the sides in toward the center. Fold the top third down and roll the whole thing toward you, creating tension as you go. You should feel the surface tighten slightly under your hands. Place it seam-side up in a banneton or bowl lined with a floured towel. Loose shaping leads to flat, spread-out loaves. Tight shaping holds the dough up during oven spring.
Cold proof overnight or room-temperature proof for 2–4 hours
If you're cold-proofing overnight in the fridge (recommended for flavor and control), cover the banneton with plastic and refrigerate for 8–16 hours. The dough will proof slowly in the cold. Before baking, do the poke test: press your floured finger gently into the dough. If the indent springs back slowly, it's ready. If it springs back immediately, give it another 2–4 hours at room temperature. If it doesn't spring back, it's overproofed and will bake flat. Room-temperature proofing takes 2–4 hours at 75–78°F and requires the same poke test.
Score decisively
A good score tells you something about your dough's readiness. If you score and the cut opens up immediately (gaping), the dough is slightly overproofed but will probably still bake reasonably well. If you score and the cut barely opens, the dough is underproofed and will burst at the sides instead of along your score. You want something in between—the cut opens moderately, and steam escapes in a controlled way. Use a sharp blade (bread lame or single-edge razor) and make one confident 1/4-inch-deep cut at a 30-degree angle.
Bake hot and covered
Preheat your Dutch oven in a 500°F oven for 30 minutes. Transfer your dough to the hot pot (carefully—it's very hot), cover, and bake at 450°F for 20 minutes. Remove the lid and bake for another 20–30 minutes until the crust is deep golden-brown. The steam trapped by the lid creates oven spring. If you bake uncovered from the start, you lose that critical early expansion. Thick, dark crust usually indicates good hydration and fermentation.
Other turns to take.
Fixing dense crumb with higher hydration
If your crumb is tight and dense but your fermentation timing looks right, try increasing hydration by 2–3% on your next bake. More water makes dough easier to work with and often produces a more open crumb. Start at 80% hydration and work up. High-hydration dough is wetter and stickier, but it ferments beautifully and opens up nicely in the oven.
Using a cold bulk fermentation for better control
Instead of fermenting at room temperature, mix in the evening, let it bulk-ferment at room temperature for 1–2 hours, then refrigerate overnight at 40°F. Finish the bulk fermentation at room temperature the next morning if needed. This gives you much more control—cold fermentation slows things down, so you can shape when you want, not when the dough demands it.
Building a stronger starter with more frequent feedings
If your starter is sluggish, switch to twice-daily feedings (morning and evening) for 3–5 days. Use a 1:1:1 ratio by weight (starter:flour:water). This builds a more active colony of yeast and bacteria. Once it's reliably doubling within 4–6 hours, you can drop back to once-daily feedings.
When it doesn't go to plan.
Keep a baking log. Write down your kitchen temperature, starter strength, bulk fermentation time, proof time, and what the crumb looked like. After five or six bakes, patterns emerge. You'll see exactly when things go wrong.
The poke test is more reliable than the clock. Every kitchen is different. Every season is different. Learn to read your dough's readiness rather than trusting a fixed timeline.
If your starter smells strongly vinegary or alcoholic, it's overhungry. Feed it more frequently or keep it at a warmer temperature. A hungry starter produces weak dough.
Dense crumb after the loaf is fully baked is usually not fixable in that loaf, but it tells you something about your next bake—add time to bulk or proofing, or make sure your starter is stronger.
Flat loaves are almost always overproofed. Err on the side of underproofing slightly—the dough will still expand significantly in the oven.
A thermometer is one of the best investments you can make. Dough temperature matters more than room temperature. Know your dough's temp, adjust your water temp, and fermentation becomes predictable.
If you're struggling, bake twice a week for a month. You'll learn more from repetition than from any guide. Sourdough teaches you as you go.
The ones that keep coming up.
My starter looks active but my bread still comes out dense. What's wrong?
Your starter might be active but not strong enough to leaven a full loaf. Try this: feed your starter, wait for it to double, then use it at its peak (not hours later). Also check your bulk fermentation temperature—if your dough is cold, it ferments slowly and may not develop enough gas, even with an active starter. A dough temperature of 75–78°F is the sweet spot.
How do I know if my dough is overproofed?
An overproofed dough will spread flat rather than hold its shape when you turn it out. During the poke test, your finger will leave an indent that doesn't spring back at all. In the oven, an overproofed loaf will spread outward rather than upward and will have a thick, dense crust. If you suspect overproofing, reduce your proof time by 1–2 hours on the next bake.
My bread rises great in the proofing basket but collapses in the oven. Why?
You're likely overproofed or your shaping is too loose. Good rise in the banneton followed by collapse in the oven means the dough has fermented past its peak. Try shorter proof times (by 1–2 hours) or stronger shaping. A well-shaped loaf should feel slightly taut and elastic, not jiggly and loose.
Does my kitchen temperature really matter that much?
Absolutely. A 5-degree difference changes your fermentation time by 30–50%. A cold kitchen (68°F) can stretch bulk fermentation to 7–8 hours. A warm kitchen (80°F) might finish in 3–4 hours. Get a thermometer and know your dough's temperature, not just your room temperature. You can adjust your mixing water to dial in the dough temperature you want.
Can I fix a dense loaf after it's baked?
No. But you can learn from it. A dense crumb tells you something was off during fermentation—either your starter was weak, your bulk fermentation was too short, or your dough was too cold. Write it down and adjust your next bake. Sourdough improves through observation, not rescue attempts.
How often should I feed my starter?
Once a day is usually enough if your starter is at room temperature and doubling reliably within 4–6 hours. If it's sluggish, feed twice a day for a few days to build strength. If it's very active and you're only baking once a week, you can feed it less often or keep it in the fridge and feed it once a week. The goal is a starter that's predictable and strong when you need it.