When is sourdough starter ready to use?
Sourdough starter is usually ready to use when it is active, risen, bubbly, and close to its peak. It should smell pleasantly fermented, not harsh, flat, or tired.
Look for peak activity
The starter should have risen clearly after feeding. The top may be slightly domed or just beginning to flatten. You should see bubbles through the side of the jar and some lightness in the texture.
The float test is not everything
A starter that floats is often active, but a starter that sinks is not always useless. Hydration, flour type, stirring, and trapped gas all affect the test. The jar tells a better story than a spoonful in water.
Timing your feed
If you want to mix dough at a specific time, the question is not just whether your starter is strong. It is whether it will peak when you need it. The starter feed calculator helps plan that window.
Use it before it collapses
Once the starter peaks and collapses, it becomes more acidic and less powerful. It may still raise bread, but timing becomes less predictable.
What ready looks like in the jar
A ready starter usually has bubbles through the sides, not just a few bubbles on top. The texture should look aerated and slightly stretched, with a surface that has risen and is either domed or just beginning to level. If you mark the jar after feeding, you should see a clear increase in height.
The smell matters too. A balanced starter smells pleasantly tangy, creamy, fruity, or mildly yoghurty. If it smells very sharp, solvent-like, or flat, it may be past its best or underfed. That does not always mean it is ruined, but it may need another feed before baking.
Why feeding ratio changes readiness
A 1:1:1 feed can peak quickly because there is not a huge amount of fresh food. A 1:3:3 or 1:5:5 feed takes longer because the starter has more flour and water to work through. Neither is automatically better. The right feed is the one that peaks when you want to mix dough.
That is exactly what the starter feed calculator is for. Enter the seed starter, flour, water, temperature, and start time, then use the result as your planning window. If the jar peaks earlier or later than expected, adjust the next feed.
When to delay mixing
If the starter has barely risen, give it more time. If it has risen and fully collapsed, feed again or accept that the dough may move more slowly. If it rises strongly after every feed, smells balanced, and behaves predictably, it is ready to do its job.
For a weak or refrigerated starter, I would rather give it one extra warm feed than mix dough with a jar I do not trust. Flour is too expensive now to let a tired starter ruin the whole bake.