Sourdough troubleshooting by symptom

Start with what happened, then check the likely causes before changing your recipe or equipment. A symptom is a clue, not a diagnosis from the finished loaf alone.

Choose the closest symptom

Compare a fully cooled slice and your notes from mixing, bulk and proof. Change one thing at a time so the next loaf tells you something useful.

Read the crumb first

Crumb by proof: under-proofed loaves are tight with a few big holes under the crust; a well-proofed loaf has even, open holes; an over-proofed loaf spreads flat with a tight, even crumb.

Most loaf problems come back to fermentation. Compare a fully cooled slice with these three, then check the symptom below. The poke test tells you when the next loaf is ready to bake.

Dense crumb or little rise

A dense loaf sits low with small, tight holes and sometimes one tunnel under the top crust. A well-fermented loaf stands taller with holes of mixed size spread through the slice.

In short: Too little fermentation, weak dough development or too much flour can limit the crumb.

Likely causes, what to check and what to change

Likely causes, most common first

Bulk fermentation stopped too early (the most common cause)
A slow or under-ripe starter
Dough too cold, so the times in the recipe were too short
Too much flour added while mixing or shaping
Not enough strength built with folds

Check first: Compare the dough's rise with your recipe, then check whether extra flour was added during mixing or shaping.
What to change: Weigh the flour and allow the dough to reach the recipe's fermentation cues. Change one variable on the next bake.
Do you need equipment?: Use the scale and bowl you already have. Mark the starting dough level; a new Dutch oven does not correct under-fermentation.

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Flat loaf or dough that collapses

A flat loaf spread before the crust set, often with a tight, even crumb from over-proofing. The loaf you want holds a high, rounded dome with steep sides.

In short: Overproofing can leave dough unable to hold its shape. Weak development is another possibility.

Likely causes, what to check and what to change

Likely causes, most common first

Over-proofed: the final proof ran too long or too warm
Loose shaping with little surface tension
Bulk fermentation ran too far, leaving a slack dough
Too much water for the flour
No steam or cover in the first 20 minutes

Check first: Did the loaf expand and then collapse, or was it slack from the start? Those histories point to different changes.
What to change: For collapse after a long proof, shorten that stage next time and watch the dough. For persistent slackness, review mixing and folds with your recipe.
Do you need equipment?: Do not buy a smaller vessel to hide the symptom. Check shaping support and dough development first.

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Gummy crumb or a wet-looking center

A gummy loaf has a darker, shiny, compressed band, usually near the base or in the middle, that sticks to the knife. Fully baked and fully cooled, the crumb is the same dry, springy color right down to the bottom crust.

In short: Underbaking and slicing before the loaf cools can both leave a gummy interior.

Likely causes, what to check and what to change

Likely causes, most common first

Sliced before it cooled for at least an hour
Under-baked: the center did not reach about 205°F
Under-fermented dough, often with a dense band at the base
Very high hydration or a lot of whole grain without a longer bake

Check first: Was the loaf fully baked according to its recipe, and completely cool before cutting? A single internal temperature is not the whole assessment.
What to change: Check the crust, loaf structure and the recipe's doneness cues. Let the next loaf cool completely before judging its crumb.
Do you need equipment?: A cooling rack and a suitable thermometer can help you observe; neither replaces sufficient baking and cooling.

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Pale crust

A pale loaf has a blond crust that softens within hours. A loaf baked uncovered long enough has a deep brown crust, darkest at the ear and the edges of the cut.

In short: The loaf may have left the oven before it browned sufficiently. Formula and fermentation also affect the sugars available for browning.

Likely causes, what to check and what to change

Likely causes, most common first

Lid left on too long or the uncovered bake too short
Oven cooler than the dial says
Over-fermented dough with little sugar left for browning
Unmalted flour (check the bag for malted barley flour)

Check first: Compare the color with the intended bread style and confirm that the oven preheated as instructed.
What to change: Follow your recipe's baking and crust-color cues. Check fermentation and salt measurement before changing the formula just to darken the crust.
Do you need equipment?: Check your oven's behavior and instructions before replacing bakeware.

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Bottom burns before the top browns

A loaf baked low in a hot pot can char on the bottom while the top is still pale. The loaf you want is brown all over, its base a shade darker than the top but never black.

In short: The base sits on the hottest metal in the oven: a preheated pot, often dark inside, low in the oven near the bottom heating element.

Likely causes, what to check and what to change

Likely causes, most common first

The pot sits on a low rack, close to the bottom heating element
A dark or black pot interior, which gets hotter than a light one
The pot stands on a preheated baking stone or steel
A long, very hot preheat (try 425°F instead of 450°F)
A long bake for a dense or whole-grain loaf

Check first: Where does the pot sit, how dark is its inside, and is it standing on a baking stone or steel? A dense or whole-grain loaf that bakes a long time gives the base longer to burn.
What to change: Move the pot up a rack and put a baking sheet on the rack below it, or line the pot's base with a thick disk of foil. You can also lift the loaf out of the pot onto the rack once the crust has set and finish it there.
Do you need equipment?: Nothing new: a baking sheet below the pot or foil in its base does the job. If you are choosing a pot, a light enamel interior browns the base less than a black one.

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Dry crumb or an overly hard crust

An over-baked or over-floured loaf has a thick, hard crust around a dry, tight crumb. The loaf you want has a crust a few millimeters thick around a moist, open crumb.

In short: Overbaking can make bread hard and dry; too much flour can also make the dough dry and heavy.

Likely causes, what to check and what to change

Likely causes, most common first

Baked too long or too hot after the lid came off
Too much flour (cups instead of grams)
Low hydration for the flour
Cooled uncovered in very dry air

Check first: Compare flour and liquid weights with the recipe, then review the actual bake duration.
What to change: Use the recipe's ingredient weights and doneness cues. Avoid adding flour simply until the dough stops feeling sticky.
Do you need equipment?: Check weighing and timing before buying a different pan.

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Crisp crust that goes soft after baking

A crust that has gone soft looks dull and leathery and may wrinkle as it shrinks onto the crumb. A crisp crust stays dry and shows fine crackles as the loaf cools.

In short: As the loaf cools, moisture from the crumb moves out to the crust. In cool, still air or a closed bag it stays there and softens the crust.

Likely causes, what to check and what to change

Likely causes, most common first

Cooled in cool, still room air, where the moisture leaving the crumb condensed on the crust
Wrapped in plastic or closed in a box, which keeps that moisture in
Taken out while the crust was still pale
Butter, milk, eggs or sugar in the dough, which make a softer crust

Check first: Did the crust soften within an hour on the rack, or overnight in a bag or box? Check the color too: a crust taken out pale holds more water than a deep brown one.
What to change: Bake until the crust is deep brown. Then turn the oven off, move the loaf to the middle rack, prop the door open a couple of inches and let it cool there. Keep a crusty loaf cut side down on a board or in a linen bag, not in plastic.
Do you need equipment?: Nothing to buy for the bake. For storage, a linen bag keeps a crust crisp for a day or two; a bread box or a plastic bag softens it.

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Side split or uncontrolled blowout

When the expansion has nowhere planned to go, the crust bursts at a weak point, often low on the side or along the seam. A deep enough score opens along the top and one edge lifts into an ear.

In short: Without an effective expansion cut, bread can burst at a different weak point.

Likely causes, what to check and what to change

Likely causes, most common first

Under-proofed: the loaf still had too much rise left
Score too shallow or too short
Seam not sealed, or loaded seam side up
No steam, so the crust set early

Check first: Look at where the loaf opened compared with where it was scored. Review the scoring pattern specified for that loaf shape.
What to change: Make the intended expansion cuts just before baking, following the recipe's technique. Scoring cannot compensate for every proofing problem.
Do you need equipment?: Use a suitable sharp scoring tool safely; decorative cuts alone may not give the loaf room to expand.

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Large holes beside tight crumb

A few big caverns beside tight crumb come from under-fermented dough or air trapped while shaping. Even fermentation and shaping spread holes of mixed size through the whole slice.

In short: Uneven fermentation or handling can leave an uneven crumb. An open crumb depends on development, fermentation and shaping together.

Likely causes, what to check and what to change

Likely causes, most common first

Under-fermented dough (big holes under the crust, tight below)
Air trapped while shaping or rolling
Too much flour on the counter folded into the loaf
Proofing in too warm a spot for too short a time

Check first: Record the dough's condition at the end of bulk and final proof, not just how long each lasted.
What to change: Follow a consistent mixing, folding and shaping sequence and compare the next cooled loaf. Do not assume more water alone will fix the pattern.
Do you need equipment?: A marked container makes rise easier to observe; it does not prescribe a universal rise target.

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Sticky dough you cannot shape

Sticky dough spreads across the bench and strings off the scraper and your hands. Dough with enough strength turns smooth and holds a rounded shape by the end of bulk fermentation.

In short: Usually too much water for the flour or too little strength built in the dough. Dough that fermented too long also turns sticky and slack.

Likely causes, what to check and what to change

Likely causes, most common first

Not enough strength built: too few folds or too little mixing
More water than this flour can hold (most white doughs turn slack and sticky above about 80%)
Over-fermented: a long or warm bulk fermentation has weakened the dough
A flour that stays sticky by nature: rye, einkorn or a lot of whole grain

Check first: Was the dough sticky right after mixing, or only after a long or warm bulk fermentation? Sticky from the start points to water or strength; sticky and slack after a long bulk points to over-fermentation.
What to change: Next time hold back some of the water, or add another set or two of folds during bulk fermentation. Handle the dough with wet hands and a bench scraper; working in more flour makes the loaf denser.
Do you need equipment?: A bench scraper is the one tool that helps: it lifts and turns wet dough without extra flour. You do not need a stand mixer; King Arthur's bakers knead very wet dough by chopping it with a bench knife and stacking the pieces.

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Starter is slow or does not rise

Put a rubber band at the starter's level after the feed. A slow starter barely moves past it; an active one doubles within about 4 to 8 hours of a 1:1:1 feed at 75 to 78°F, domed and full of bubbles.

In short: Starter activity changes with feeding ratio, flour, culture and temperature.

Likely causes, what to check and what to change

Likely causes, most common first

Kitchen too cold (below about 70°F)
Fed too rarely or used long after its peak
Still young (under two weeks)
Only bleached white flour in the feed

Check first: Mark its level after feeding and watch for a repeatable rise and peak. Go by the rise, not the clock.
What to change: Keep a consistent feed and temperature so you can compare cycles. Times for a cool starter won't hold on a warm counter.
Do you need equipment?: A clean food-safe jar is enough for watching it. A warmer only helps if your kitchen is too cold.

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Starter has mold or pink/orange discoloration

Fuzzy spots of any color, or pink or orange streaks, mean the starter has spoiled: throw it out and clean the jar. A grey or dark liquid on top is hooch, a sign of a hungry starter: pour it off or stir it in, then feed.

In short: These are discard signs, not a feeding-ratio problem.

Likely causes, what to check and what to change

Likely causes, most common first

Mold (fuzzy spots of any colour): throw it out
Pink or orange streaks: unwanted bacteria, throw it out
A smell other than the usual sour or alcohol smell: spoiled, throw it out
Grey or dark liquid: hooch, harmless
A dry crust: dried starter, not mold

Check first: Look for mold, pink/orange discoloration, or a smell that is not the usual sour or alcohol smell. Do not taste the starter to investigate.
What to change: Discard it rather than trying to rescue it with another feed. Clean the container before starting again.
Do you need equipment?: A new appliance is not the remedy. King Arthur's sourdough FAQ distinguishes these signs from an alcohol smell.

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Loaf is more sour than you want

Sourness cannot be seen in the crumb, but it can in the jar. A starter used long after its peak has fallen back below its high mark and may carry hooch; used at the dome of its peak, it gives a milder loaf.

In short: Recipe, fermentation time and temperature affect sourness; the starter's smell is not the only factor.

Likely causes, what to check and what to change

Likely causes, most common first

Starter used long after its peak
Long or warm bulk fermentation
Long cold proof
A stiff starter kept cool (more acetic acid)

Check first: Compare the current recipe and refrigerator rest with the loaf you preferred.
What to change: Choose a recipe aimed at a milder loaf and record its fermentation conditions. Do not under-ferment a dough merely to meet a shorter clock time.
Do you need equipment?: Use your existing temperature and timing observations before changing equipment.

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Baking references for this guide: Dense bread, flour measurement, pan size and rising; Dough strength, fermentation and open crumb; Overproofed dough and collapse; Bread doneness, crust color and cooling before slicing; Starter condition, gluten, sourness and ingredient roles; Why a Dutch oven burns the bottom crust, and foil in the pot to prevent it; Keeping the bottom from burning in a Dutch oven: rack, baking sheet, preheat and lifting the loaf out; Why a crisp crust softens as the loaf cools, and cooling it in the switched-off oven; Lean doughs, steam and stone baking for a crusty loaf; enriching ingredients soften the crust; Scoring, preheating and baking sequence; Why dough is sticky when shaping: too much water, too little strength or over-proofing; Kneading very wet dough by hand without adding flour (the chop-and-plop); Starter feeding intervals at a constant 1:4:4 ratio (King Arthur Baking, The Perfect Loaf, Brod & Taylor).