Free baker's tool
Bulk fermentation calculator
Bulk is where most loaves are won or lost. Tell us four things about your dough and we'll give you a target rise and a realistic window — then start the timer and bake by the dough, not the clock.
100 g starter with 500 g flour is 20%.
Your bulk
Rise 45%
in roughly 4 hr 42 min – 6 hr 42 min
Stop when the dough is domed, jiggly and full of small bubbles at the edges of the container. It should feel airy, not soupy.
A comfortable middle range: the dough gives you plenty of visual signals before it over-ferments.
Ignore the clock and read the dough — domed top, jiggle, bubbles along the sides. Then read the crumb after baking: tight and gummy means under-fermented, flat and grey-holed means over. Write down the temperature and rise every bake and the numbers become yours.
These are guides, not guarantees — always trust the dough over the clock.
00:00:00
- 1 hr 26 min — First set of stretch and folds — the dough should feel tighter already.
- 2 hr 51 min — Halfway. Look for a few bubbles at the surface and a smoother top.
- 4 hr 17 min — Last fold, then leave it alone. Mark the level on the container.
- 5 hr 42 min — Target reached — check for about 45% rise before shaping.
The timer runs while this tab is open.
Dough temperature vs. target rise
At 20% starter with mostly white flour. The colder the dough, the more it has to rise before it is ready. Screenshot it, or print the quick card.
| Dough temp | Target rise | Plan for |
|---|---|---|
| 80°F / 26.7°C | 30% | 3 hr 30 min – 5 hr 30 min |
| 79°F / 26.1°C | 35% | 3 hr 48 min – 5 hr 48 min |
| 78°F / 25.6°C | 40% | 4 hr 6 min – 6 hr 6 min |
| 77°F / 25°C | 40% | 4 hr 24 min – 6 hr 24 min |
| 76°F / 24.4°C | 45% | 4 hr 42 min – 6 hr 42 min |
| 75°F / 23.9°C | 50% | 5 hr – 7 hr |
| 74°F / 23.3°C | 55% | 5 hr 36 min – 8 hr |
| 73°F / 22.8°C | 60% | 6 hr 12 min – 9 hr |
| 72°F / 22.2°C | 65% | 6 hr 48 min – 10 hr |
| 71°F / 21.7°C | 70% | 7 hr 24 min – 11 hr |
| 70°F / 21.1°C | 75% | 8 hr – 12 hr |
| 69°F / 20.6°C | 80% | 8 hr 48 min – 12 hr 48 min |
| 68°F / 20°C | 85% | 9 hr 36 min – 13 hr 36 min |
| 67°F / 19.4°C | 90% | 10 hr 24 min – 14 hr 24 min |
| 66°F / 18.9°C | 95% | 11 hr 12 min – 15 hr 12 min |
| 65°F / 18.3°C | 100% | 12 hr – 16 hr |
Three habits make these numbers reliable: take the dough's own temperature rather than the room's, judge by percentage rise instead of the clock, and record the temperature, rise and result of every bake until the pattern is yours.