Sourdough Starter Problems: Not Rising, Runny, or Smelling Off
A starter that won’t rise, turns thin and watery, or smells like nail polish is usually the first real wall new bakers hit, and it can feel like something is fundamentally broken. Most of the time, it isn’t. A starter is a jar of living microorganisms, and nearly every problem below comes back to the same few things: food, temperature, water, and time. Find your symptom, match it to the cause, and change one thing at a time.
The Short Answer
A starter that won’t rise is usually too young, underfed, too cold, or being fed the wrong ratio of flour to water. A runny starter, a layer of dark liquid (hooch), and a nail polish or vinegar smell all point to the same thing: a hungry starter that has run out of food and turned acidic. Match your situation to the specific cause below rather than changing everything at once.
Start here: what is your starter doing?
- It isn’t doubling after a feeding. Jump to “Starter not rising: six causes.” The usual suspects are a young starter, a cold kitchen, an off feeding ratio, or sometimes the tap water.
- It’s thin, pourable, or has dark liquid on top. Jump to “Starter runny or watery.” Most of the time it is simply hungry.
- It smells like nail polish, acetone, or sharp vinegar. Jump to “Starter smells like nail polish or vinegar.” It has gone hungry long enough to turn noticeably acidic.
The hungry-starter reset (the fix behind most of these)
Several of the problems below end in the same fix, so here it is once. If your starter has gone too long between feedings, you may see a layer of dark liquid on top called hooch, a thin watery texture, or a sharp smell. Here is what to do:
- Don’t pour the hooch off. Stir it back in. At this point the whole jar is very acidic, so it isn’t ready to bake with yet.
- Rescue a small portion. Pull out about 20 g and feed that portion at a 1:10:10 ratio (1 part starter, 10 parts flour, 10 parts water, by weight). Once it doubles and fully ferments, that portion is usable.
- Keep the rest. Don’t throw the acidic remainder away. Stir in a few tablespoons of flour until it is back to a thick, shaggy waffle-mix consistency, then put it back in the fridge overnight.
- Use it later. Next time you’re ready to bake, pull a portion from the jar and activate it the same way, or use it in your discard recipes.
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Starter not rising: six causes
Cause 1
Your starter is still young. It simply hasn’t built up enough wild yeast and bacteria yet to rise reliably, and that has nothing to do with how many days have passed on a calendar.
The Fix
Judge readiness by a pattern, not a date. Once your starter more than doubles in size after a single daily feeding, three days in a row, it’s ready to bake with. How long that takes varies a lot with your kitchen’s temperature, humidity, and the flour you’re using. My own first starter took about 5 days, but a new starter can just as reasonably take a full week, or two, or even three. All of that is normal. Let the three-day doubling pattern be your marker instead of the calendar. Not sure whether your starter is actually ready? The float test is less reliable than people think, so see Why the Float Test Lies to You before you trust it.
Cause 2
Feedings have been inconsistent, so the yeast population never gets the chance to establish a rhythm.
The Fix
Feed on a consistent schedule, but match the ratio to your situation. If you’re building a brand new starter from scratch, feed once daily at 1:1:1 (equal parts starter, flour, and water by weight), discarding down before each feeding. If you have an established starter that has just gone dormant, feed it at a more diluted 1:10:10 ratio, and it should be active and ready to use again within about 8 to 10 hours.
Cause 3
The kitchen is too cold, which slows microbial activity significantly.
The Fix
Move the starter somewhere warmer, like the top of the fridge or a turned-off oven with the light on.
Cause 4
The flour-to-water ratio is off, or you switched flour types recently without adjusting.
The Fix
If your starter looks too liquidy, add more flour until it looks like a shaggy waffle mix, thick, not pourable, then let it ferment until it doubles or triples before you use it. Your starter feeds off that flour, so it’s better to have it a bit thick right after feeding than loose. It will relax and loosen back up on its own as it ferments.
Cause 5
Your tap water could be slowing the starter, though the evidence is thinner than most advice suggests. A 2024 study found that chlorine at normal tap water levels did not noticeably change the bacteria in developing starters. Chloramine, a different disinfectant that boiling does not remove, was never tested.
The Fix
Run a side by side jar test with tap water and bottled spring water before you change anything. If the bottled jar clearly wins, switch to bottled water or a filter rated for chloramine. The full test is in Can You Use Tap Water for a Sourdough Starter?
Cause 6
The starter hasn’t been fed in too long and has gone dormant, sometimes with a layer of hooch on top.
The Fix
Follow the hungry-starter reset above.
Starter runny or watery: four causes
A runny starter can look alarming, especially if you’re used to seeing thick, pancake-batter consistency in photos online. A thin starter isn’t automatically a dead one. That thin, watery texture, or the dark liquid called hooch, usually means your starter has consumed most of its available food and needs to be fed sooner or more often.
Cause 1
The starter has gone too long between feedings and has run out of food to consume.
The Fix
Follow the hungry-starter reset above.
Cause 2
Your feeding ratio is too water-heavy for the consistency you actually want.
The Fix
Adjust your ratio slightly toward more flour if you want a thicker, more manageable consistency.
Cause 3
Your kitchen is warm, which speeds up fermentation and means your starter runs out of food faster than a recipe written for a cooler climate assumes.
The Fix
Feed more frequently if it’s consistently hungry before the next scheduled feeding, or move it to the fridge between bakes if you can’t keep up with an accelerated schedule.
Cause 4
Your flour has less gluten strength, which naturally holds a looser structure.
The Fix
Know that a looser texture from a different flour isn’t automatically a problem. Adjust your ratio toward more flour only if you specifically want a thicker consistency.
Starter smells like nail polish or vinegar
This is one of those things that makes new bakers want to toss the whole jar and start over, but a strong smell is usually your starter communicating something specific, not dying.
A nail polish or acetone smell comes from excess alcohol, as the yeast runs low on food. A vinegar smell comes from the acetic-acid bacteria pulling ahead. Both mean your starter has gone hungry long enough to turn noticeably acidic. Sometimes that shows up as a layer of dark liquid on top, but not always: a starter can smell this sharp and acidic with no visible liquid at all, and it means the same thing either way.
Cause
Your starter has gone hungry long enough to turn noticeably acidic, with or without visible hooch.
The Fix
Treat the starter as acidic even on days when there’s no visible liquid but the smell is still sharp. It isn’t a starter you want to bake with directly yet, so follow the hungry-starter reset above. It calms back down within a feeding or two.
Quick answers
How long does a new starter take to rise reliably? There is no fixed number of days. Look for the pattern: more than doubling after a single daily feeding, three days in a row. For some starters that takes about 5 days, for others up to three weeks.
Is a runny starter dead? No. A thin starter is usually a hungry starter. Feed it.
Should I pour off the hooch? No. Stir it back in, then use the hungry-starter reset.
Can I bake with a starter that smells like nail polish or vinegar? Not directly. It is very acidic at that point. Rescue a small portion first, as described in the hungry-starter reset above.
Desi’s Note
Every starter I’ve ever grown had some slow, unremarkable days where nothing seemed to happen. Then one day it just clicked. Don’t audit yourself out of the process before it’s had a fair chance to close.
A runny starter isn’t a red flag on the balance sheet, it’s just telling you it’s hungry sooner than expected. And a starter that smells like a nail salon isn’t broken, it’s just loud about being hungry. Feed it, and it calms back down.
Want To Know The Science Behind This?
If you want the deeper “why” behind what’s actually living in your starter and how it establishes itself, check out our Sourdough Science article: “Starter Microbiology 101: What’s Actually Living in That Jar” click here →.
More Resources
For a printable reference, grab the Starter Troubleshooting Quicksheet. To sanity-check your ratios, run them through the Sourdough Calculator. New to the terms? Jargon like starter, wild yeast, hooch, discard, feeding ratio, fermentation, and gluten is explained in plain English in the full Sourdough Glossary. Still not sure what is wrong? Go back to What’s Wrong With My Loaf? for the rest of the troubleshooting guides.
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