Sourdough Bulk Fermentation Calculator
Bulk fermentation is the slowest step in a sourdough timeline and the easiest one to misjudge. Enter your dough temperature, starter %, and mix time to estimate when bulk will be done — plus a target rise % and three fold times to plan against.
75°F
60°F90°F
Comfortable room temperature
End bulk around
Today 5:54 PM
between Today 5:09 PM and Today 6:39 PM
Look for
40% rise
35–45% range expected
Approximately 5h of bulk
Signs bulk is done
- Dough looks puffy and aerated
- Jiggles slightly when the bowl is shaken
- Small bubbles visible on surface and sides
- Passes the poke test — slow rebound, doesn’t spring back fully
Plan your folds
- Fold 1 — Today 1:24 PM
- Fold 2 — Today 2:09 PM
- Fold 3 — Today 2:54 PM
Fold during the first half of bulk fermentation to build dough strength.
Use these times as a starting point, not a stopwatch. Always confirm with visual signs above. Bulk fermentation is affected by flour type, hydration, and starter health, which this calculator doesn’t yet account for.