Sourdough Fermentation Chart
Use your dough temperature, starter percentage and dough size to build a practical sourdough fermentation chart with a range rather than false precision.
Estimated bulk window
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Estimated bulk window
— hours
Judge the dough by rise and texture, not the clock alone.
| Milestone | Timing | What to look for |
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How this sourdough fermentation chart computes
This sourdough fermentation chart starts from the supplied reference point: bulk fermentation at 25 °C with 20% starter takes about 4–5 hours to reach a 50% rise. It adjusts that window for temperature, inoculation percentage and your dough-size factor.
The clock is only a guide. Bulk is judged by a 30–50% rise, a domed jiggly surface and bubbles at the container edge; an aliquot jar—a small sample of the same dough in a straight-sided container—measures rise more reliably than the main vessel.
The model is clamped outside roughly 15–32 °C (59–90 °F), where yeast and bacteria diverge and the estimate breaks.
estimated hours = 4.5 × 2^((25 − temperature °C) / 10) × ((100 ÷ starter %) ÷ 5) × dough-size factor The 25 °C, 20% starter anchor uses 4.5 hours, the midpoint of the supplied 4–5 hour reference. Results are windows, not guarantees.
Sourdough fermentation chart FAQ
What temperature range does this chart cover?
It estimates only from roughly 15–32 °C (59–90 °F). Outside that band it shows a warning instead of a time.
What does the starter percentage mean?
Enter the starter percentage used for the dough. The model treats 20% starter as its bulk-fermentation reference point.
What is the dough-size factor?
Use 1 for your reference batch. Use a larger or smaller relative factor when comparing batch sizes; the tool does not assume a gram baseline.
Should I wait for the exact end time?
No. Use the window alongside the visual cues: a 30–50% rise, a domed jiggly surface and bubbles at the container edge.
Is this chart a guarantee?
No. It is a reference estimate based on the supplied model. Dough conditions vary, so judge fermentation by the dough as well as the clock.