Starter School
Understand Your Starter
Start with a question. Find practical answers and explore the science behind them.
How do I know if my starter is actually active?
Watch for bubbles — they're your only real evidence of yeast activity. A rising volume is a bonus, but bubbles on the surface mean the yeast is eating. If you see no bubbles at all after 24 hours, the culture hasn't started eating the last feed yet. Give it more time before feeding again.
Explore the science: What CO₂ tells you about starter activity →
Can I overfeed my starter?
Yes. A starter is an ecosystem — when you discard and refeed, you remove 80% of the yeast population you just grew. Feed too early and the yeast hasn't had time to recover its numbers. Over time, this weakens the culture. It is always better to feed a little late than too early.
Explore the science: Why feeding too often can weaken a starter →
When is the right time to feed?
Feed when your starter is clearly past peak — volume is dropping, surface bubbles are starting to recede. If you're unsure, wait longer. You can't starve your starter in a single cycle. Watching the bubbles will tell you more than any clock.
Why does my starter smell like alcohol or nail polish?
In an established starter, an acetone smell means it has consumed all available sugars and the yeast has started producing alcohol. It's genuinely hungry. Try a larger ratio (1:3:3 or 1:4:4) or feed more frequently. In a brand-new starter (first 3 days), strange smells including alcohol are completely normal — that's bad bacteria burning off, not a problem.
My starter isn't rising at all. Did I kill it?
Almost certainly not. A starter is very hard to kill. The most common cause of no rise is temperature — below 18°C, activity slows dramatically and a rise may not be visible at all. Move it somewhere warmer (24–26°C) and wait. If you're in the first 10 days, quiet phases are completely normal. Look for any bubble activity at all, even tiny ones, before worrying.
Does the type of flour matter?
A lot, especially in the early days. Whole wheat and rye flour carry more wild yeast and bacteria on the grain hull — using 100% refined flour to build a new starter has a high failure rate. Once your starter is established, you can switch to bread flour or all-purpose, but a blend with some whole grain will always ferment faster and more reliably.
How do I know when my starter is ready to bake with?
The standard check: after a 1:2:2 feed at around 23°C, your starter should roughly double in volume within 4–7 hours. If it passes this on three consecutive days, it's ready. Speed to peak matters more than height — a starter that doubles in 4 hours is stronger than one that triples in 10.
What's the white liquid on top of my starter?
In a new starter, it's almost always water separation — not "hooch." Hooch (grey-black liquid, alcohol smell) only forms in a mature, well-established starter that has completely exhausted its food. If yours is less than 10 days old, just stir it and keep going. If it's mature and you see a dark liquid pooling on top, feed it — it's very hungry.
Is my starter dead? It bubbled on day 2 but now it's completely flat.
It's not dead — it's going through a normal transition. Those early bubbles were caused by unwanted bacteria (Leuconostoc), not yeast. As acidity builds, those bacteria die off and things go quiet. The real yeast and lactic acid bacteria are slowly colonising in the background. Keep feeding and it will start rising again in a few days.
What's the dark liquid on top? It smells like nail polish.
That's hooch — alcohol produced when the yeast runs out of food. It's safe. Pour it off or stir it back in (stirring in gives a more sour result). Either way, feed your starter now. If it keeps happening, increase your ratio — try 1:3:3 instead of 1:1:1.
How do I know when my starter is at its peak?
Watch the top. At peak, the surface is domed — slightly rounded in the centre. Once it starts to flatten or sink in the middle, it has passed peak and is deflating. Volume-wise, a healthy mature starter typically doubles or triples after a feed. Use it at the dome, not after.
What's the difference between a 1:1:1 and a 1:5:5 feeding ratio?
The ratio controls how fast your starter peaks. 1:1:1 — less food, peaks in 4–6 hours, good if you're baking the same day. 1:5:5 — more food, peaks in 8–12 hours, good for an overnight schedule (feed before bed, bake in the morning). Match the ratio to when you actually need it ready.