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Float Test

Starter that floats is usually ready; one that sinks may still be.

Float Test: spoonful of starter floating in a glass of water
A spoonful that floats is full of gas. One that sinks may still be ready.

A quick check on sourdough starter activity. Drop a spoonful of starter into room temperature water. If it floats, it's full of gas and almost certainly ready to bake with. If it sinks, it may need more time or another feeding, but a sinking starter isn't proof it's not ready: whole grain, rye, and very wet starters can be at their peak and still sink. Use it alongside the rise, the bubbles, and the smell.

Put this into practice

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Use the starter guide for maintenance, recovery, feeding, and common starter problems.

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By Henry Hunter · Updated

Henry's notes from the bench

  • Use room temperature water for the test. Cold water can give false negatives.
  • I trust the jar more than the float. If it has doubled, smells pleasantly sour, and is domed with bubbles, it's ready.

Connected terms

Sourdough StarterFeeding
Report a correction for this termCorrection inbox owner: Henry Hunter · Reply within 7 days