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Starter troubleshooting

Your starter is alive — it communicates. Here's how to read what it's telling you and what to do about it right now.

Liquid on top (hooch)

Why it happens

Your starter is hungry — the alcohol is a byproduct of yeast running out of food.

What to do

Discard and feed immediately. Increase feeding frequency or ratio (try 1:5:5). Hooch isn't mold; stir it in or pour it off — either works.

No rise after 12 hours

Why it happens

Too cold, too acidic, or the culture is weak. Below 18°C, activity stalls; above 90% hydration with weak flour, it collapses.

What to do

Move to a warmer spot (22–26°C is ideal). Feed with a fresh ratio. If it's been weeks without feeding, do two back-to-back feeds 12 hours apart before you judge.

Smells like nail polish remover

Why it happens

Ethyl acetate — a sign of stress fermentation, usually from too much acidity or insufficient food.

What to do

Feed at a higher ratio (1:5:5 or 1:10:10) for two or three cycles. The acetone smell should give way to a yoghurt-and-fruit profile within 48 hours.

Discard and restart

Pink or orange streaks

Why it happens

Bacterial contamination — Serratia marcescens. Not mold, but not safe.

What to do

Discard the entire starter. Clean your jar with hot water and white vinegar. Start fresh — this one can't be saved.

Discard and restart

Fuzzy growth on top (mold)

Why it happens

Cross-contamination from airborne spores — more common in humid kitchens or if the jar was near fruit.

What to do

Discard and start fresh. If the mold is only on the very top of an otherwise healthy starter, some bakers carefully remove it and feed the remainder — your call. When in doubt, start fresh.

Sour but won't rise bread

Why it happens

Overfermented before use, or used at the wrong stage — past peak.

What to do

Use your starter at peak (just domed, not collapsed). Shorten the time between feeding and baking, or increase the starter percentage in your loaf to compensate for reduced lift.

Log it for next time

The best diagnostic tool is your own history. Start a starter diary in Levain — feed dates, ratios, peak times, and notes.

Start your starter diary