Why Is My Sourdough Dense? 9 Causes, and How to Tell Which One You Have

My first “successful” sourdough loaf came out of the oven looking perfect and cut like a brick. Dense, gummy in the middle, the kind of crumb you could use as a doorstop. I blamed the flour. Then the starter. Then, briefly, the oven, which had done nothing wrong in its entire life. It just had no idea what temperature it was actually running at, and neither did I.

It took me 6 loaves to figure out it wasn’t one thing. It was a different thing every time, and most of them came down to baking in a small apartment kitchen with no proofing box, no consistent temperature, and a starter I fed on a schedule that suited me instead of the room I kept it in.

Dense sourdough isn’t a mystery and it isn’t bad luck. It’s a symptom, and symptoms point to causes. Here’s how to work out which one is yours, starting with the fastest way to check.

Diagnose Your Loaf in 30 Seconds

Match what you’re seeing to a row below. Each one stands on its own, so jump straight to the one that matches your loaf.

Symptom	Likely Cause	Fix
Dense all the way through, barely any holes	Starter wasn’t active enough at mix time	Only use starter that’s doubled within 4 to 8 hours at 70 to 75°F (21 to 24°C), checked with a marker, not guessed
Dense and gummy, still feels wet even fully baked and cooled	Under-fermented, pulled from bulk rise too early for the kitchen’s temperature	Bulk ferment to the rise target for your temperature, not a fixed clock time (see below)
Flat and spread out, sour or vinegary smell	Over-fermented, left past peak	Pull 30 to 60 minutes earlier next time; use the poke test, not the clock
Dense and tight, dough felt stiff and hard to work with	Hydration too low for the flour you’re using	Match hydration to your flour: 60 to 65% for all-purpose, 65 to 70% for bread flour
Flat and spread out, but the crumb itself is dense and tight (not sour-smelling)	Gluten never developed enough to hold structure	Add 4 sets of stretch and folds, 30 minutes apart, during bulk rise
Tears on top, or a caved-in top	Under-scored, or over-handled between shaping and the oven	Score at least 1/4 inch (6mm) deep right before baking; handle the dough only twice, shape once, load once
Pale crust, oven spring barely happened	No steam in the first 20 minutes of baking	Trap steam with a covered pot, or a metal bowl inverted over the loaf on a tray
Bake times keep drifting, or one side of the loaf is denser than the other	Oven or proofing spot running hotter or colder than you think	Check with a $6 oven thermometer, don’t trust the dial or the oven light blindly
Dense despite doing everything else right	Old or low-protein flour	Switch to fresher bread flour if you can get it, or adjust hydration down for all-purpose

If more than one of these sounds familiar, start with starter strength. It’s the most common cause and the easiest to fix without buying anything.

Is Your Starter Ready? (Most Dense Loaves Start Here)

Short answer: if it hasn’t doubled in a jar within 8 hours of feeding, it’s not ready, and using it anyway is the single biggest cause of dense bread.

I fed my starter every morning before work and used it every evening, on a schedule built around my calendar, not its actual activity. In a cold apartment kitchen in winter, an 8-hour starter can turn into a 14-hour starter and nobody tells you that by text. Mark the level with a rubber band or a strip of tape right after feeding, then check it. Doubled and full of bubbles within 4 to 8 hours at 70 to 75°F (21 to 24°C) means it’s ready. Still flat at hour 8 means wait, don’t bake.

No sunny spot and a genuinely cold kitchen? The top of the fridge runs a few degrees warmer than the room. So can the inside of an oven with just the light left on, though don’t assume that number, check the section on ovens below. It varies more than people think.

Is Your Hydration Matched to Your Flour? (Dense and Gummy Can Mean Either Direction)

Short answer: dough that’s stiff and hard to work usually means it’s too dry for the flour you’re using, but “too dry” is relative to what’s in your bag, and pushing hydration up isn’t automatically the fix.

60 to 65% hydration (60 to 65g water per 100g flour) is a normal, correct starting point, especially with all-purpose flour, and it’s not a mistake you need to grow out of. Where hydration actually causes a dense, gummy loaf is going too far in either direction: under about 55% is genuinely too dry to develop properly, and pushing all-purpose flour up to 70%+ (a ratio meant for bread flour) gives you a slack dough that doesn’t have the gluten strength to hold that much water, which collapses into tight and gummy rather than open. If you’re using bread flour, 65 to 70% is a reasonable place to aim for a more open crumb. If you’re using all-purpose, stay at 60 to 65% rather than chasing the wetter ratios you’ll see in bread-flour recipes online.

Did You Pull the Dough Too Early? (Gummy Middle, and 2 Other Things to Rule Out First)

Short answer: a gummy, wet-feeling crumb can mean under-fermentation, but check the other 2 common causes first, because they’re easier to fix and easier to misdiagnose as fermentation.

First, rule out underbaking: an instant-read thermometer should show 205 to 210°F (96 to 99°C) in the center of a fully baked loaf. Second, rule out cutting it too soon: sourdough keeps cooking internally as it cools, and slicing within the first hour will look and feel gummy even on a loaf that baked perfectly. Let it rest on a rack for 1 to 2 hours before you cut it and judge the crumb.

If it’s genuinely under-fermented, “bulk fermentation” doesn’t mean the dough doubles, and the target isn’t fixed either. It depends on temperature: roughly 75% bigger at 70°F, 50% bigger at 75°F, and closer to 30% bigger at 80°F. In a cooler apartment, that means bulk fermentation naturally takes longer and needs a bigger rise before it’s ready, not a shorter one. Going by a fixed clock time instead of what the dough is actually doing (understandable, when you’re timing it around a workday) means you’ll pull it early more often than not in a cool kitchen. Poke it instead. A slow spring-back with a slight dent left behind means it’s ready. An instant, full spring-back means it needs more time.

Did It Sit Too Long Instead? (Sour Smell, Flat Loaf)

Short answer: if the dough smells more like vinegar than bread and the loaf came out flat rather than tall, you likely over-proofed it.

This is the opposite problem and just as common once you overcorrect for under-fermenting. An over-fermented dough has used up the structure that was holding it up, so it spreads instead of rising in the oven. Next bake, pull it 30 to 60 minutes earlier and use the poke test above instead of a fixed clock.

Is Your Gluten Doing Its Job? (Flat Loaf, Dense Crumb, No Sour Smell)

Short answer: if your loaf spread sideways more than it rose and the inside is tight and dense, but it doesn’t smell over-fermented, the dough likely never built enough structure to hold itself up in the first place.

Stretch and folds are the fix, not kneading for 15 minutes like a yeasted dough. During bulk fermentation, wet one hand, grab a side of the dough, stretch it up, and fold it over the top. Turn the bowl a quarter turn and repeat 3 more times. Do that whole set 4 times, 30 minutes apart. It takes about 2 minutes total and it’s the difference between a loaf that holds its shape and one that spreads like a pancake.

Did the Dough Tear or Deflate Before It Hit the Oven?

Short answer: visible tears or a caved-in top usually mean one of two things: it wasn’t scored deep enough to control where it splits, or it got knocked around too much on the way to the oven.

If you didn’t score it, or only scratched the surface, the oven spring looks for the fastest way out and tears the loaf somewhere you didn’t choose. Score at least 1/4 inch (6mm) deep with a sharp blade or razor, held at a low angle, right before it goes in. Combine that with handling it only twice: shape it once, on a lightly floured surface, then move it directly into the pan or basket you’re baking it in. Don’t reshape it if it looks a bit off. It looks worse handled twice than it does slightly lopsided.

Are You Getting Steam in the First 20 Minutes?

Short answer: a pale crust and a loaf that barely rose in the oven, even though it looked fine going in, usually means there was no steam trapped around it early in the bake.

Steam keeps the crust soft long enough for the dough to expand before it sets. No Dutch oven in a small kitchen isn’t a dealbreaker. Put the dough on a tray, invert a large metal bowl over it, and bake covered for the first 20 minutes at 450°F (230°C). Uncover, drop to 425°F (220°C), and bake another 20 to 25 minutes until deep golden.

No Dutch oven at all, not even a spare bowl? See How to Bake Sourdough Without a Dutch Oven for 3 ways to get the same crust with what you’ve already got.

Not sure your starter is strong enough to bake with yet? Build one from scratch and learn to read it, including the stretch where it looks dead.

Is Your Oven Running the Temperature You Think It Is?

Short answer: if your bake times keep drifting or one side of the loaf is consistently denser, an inaccurate oven or an unreliable proofing spot is a likelier cause than anything about your technique.

The oven-light trick (proofing dough in the oven with just the interior bulb on) is common advice, and it can work, but don’t trust it blindly. Depending on the oven, the bulb alone can add anywhere from 5°F to 20°F over room temperature, and some ovens run warm even with everything switched off. Sourdough proofs best somewhere around 75 to 82°F (24 to 28°C). A $6 oven thermometer sitting on the rack next to the dough tells you what’s actually happening instead of what the dial claims. It’s the single most useful apartment fix on this list, because a rental oven’s dial being wrong isn’t something you can see, taste, or guess your way around. You can only measure it.

Is It the Flour? (Last Thing to Check, Not the First)

Short answer: if you’ve ruled out the other 8 and it’s still coming out dense, check whether you’re using bread flour or all-purpose, because that protein difference matters more than people expect.

Bread flour usually runs 12 to 13% protein, all-purpose 10 to 11%. That gap sounds small, but it changes how much gluten structure you can build with the same amount of stretching and folding. All-purpose can still work, it just needs the hydration matched to it (see above) rather than pushed toward bread-flour ratios. If a bag’s been open and sitting half-used in your pantry for a year or more, that’s also worth ruling out before you blame your technique.

Where to Start Tonight

You don’t need to fix all 9 of these before your next bake. Pick the one row from the table that matches your last loaf, fix just that one thing, and bake again. That’s genuinely how I got from doorstop to something I’d serve to other people, one variable at a time, not one perfect weekend.

If you want the feeding schedule, hydration ratios, and bake times written out so you’re not doing the maths from a blog post while your hands are covered in dough, that’s exactly what I built into The Micro-Bakery Handbook once I’d made enough of these mistakes to write them down properly.

And if fermentation in general still feels like guesswork, the fermentation troubleshooting guide covers the rest of it, sauerkraut, kimchi, and the “is this supposed to smell like that” questions that come with all of it.