11/02/2026
Bulk fermentation time depends on the temperature of the dough, and the gap is large. In my chart for a lean dough with 20% starter, 72°F takes 4.5 to 7 hours and 78°F takes 3.5 to 4.5 hours. Every 15°F or so of extra warmth roughly doubles the speed. My kitchen runs in the high 70s to low 80s°F in July, so I start checking well before the low end of the range. The chart and the hot kitchen fixes are at https://thebakekeeper.com/sourdough-bulk-fermentation-time-by-temperature/
How long sourdough bulk fermentation takes from 70 to 90°F (21 to 32°C) dough temperature at 20% starter, plus fixes for a hot kitchen.