Sourdough Starter Troubleshooter

Pick what you're seeing or smelling — get the most likely cause and exactly what to do next.

Choose a symptom on the left to see the cause and the fix.

Most starter panic is really just hunger

The vast majority of sourdough starter scares come down to one thing: the culture is hungry. A sharp acetone smell, a layer of dark hooch, a fast rise-and-collapse — these are all the same message in different forms, namely feed me more often. None of them mean your starter is ruined.

The second big category is a young or cold starter that simply hasn't hit its stride. New cultures routinely take one to two weeks of steady feeding before they double on schedule, and a chilly kitchen or chlorinated tap water can stretch that out further. That's slow, not broken — warmth, a consistent schedule, and a little whole grain flour usually wake it up.

The one genuine exception is mold. Fuzzy growth or pink and orange streaks are not part of a normal starter and can't be rescued by scraping. When that shows up, the safe move is to discard everything and start fresh in a clean jar. Everything else on the list above is fixable with a feed and a little patience.

Frequently Asked Questions

Why does my sourdough starter smell like acetone?
An acetone or nail-polish smell means your starter is underfed. When the culture runs out of flour to eat, it produces alcohol and solvent-like compounds. Feed it more often and at a higher ratio, keep it warm, and the sharp smell gives way to a pleasant tangy-yeasty aroma within a day or two.
Is the liquid on top of my starter bad?
No. The dark liquid, called hooch, is alcohol the starter made when it got hungry. It's a feeding signal, not spoilage. Pour it off for a milder flavour or stir it in for extra tang, then feed. Persistent hooch just means you should feed more often or at a higher ratio.
How do I know if my starter has mold?
Mold looks fuzzy and raised — white, green, or black — or shows pink and orange streaks. That is different from hooch or a flat, bubbly surface. Fuzzy or coloured growth means you should discard the whole starter and begin again with a clean jar; it is not safe to scrape off and reuse.
How long until a new starter is ready to bake?
A brand-new starter usually needs 7 to 14 days of consistent daily feeding before it reliably doubles and can leaven bread. If it stalls, check the temperature (aim for 24-27 C), use dechlorinated water, and add some whole grain flour. Slow early activity is normal, not a failure.
Can I revive a neglected starter from the fridge?
Usually yes, as long as there's no mold. Take it out, discard most of it, and feed once or twice a day at room temperature. Within two to four feeds a healthy fridge starter typically bounces back to a strong, doubling culture. If you see fuzzy or coloured growth, discard and start over.

📚 Keep your starter thriving