Fermentation timing
40% Rye Hearth Loaf — Timing by Kitchen Temperature
Baseline: 3.5h bulk + 8h proof at 76°F. Adjust for your kitchen below.
The full 40% Rye Hearth Loaf schedule (76°F baseline)
40% Rye Hearth Loaf is a hearth-style sourdough from Germany. From a ripe levain to a cooled loaf it runs about 13.5 h of dough-day time on top of a ~5-hour levain build. Every duration below is the 76°F baseline — scale it with the temperature table lower down for your own kitchen.
| Stage | Duration | Elapsed from mix |
|---|---|---|
| Levain build to peak (before mixing) | ~5 h | −5 h |
| Autolyse (flour + water rest)builds extensibility before the levain goes in | 30 min | 30 min |
| Mix — add levain & salt | 18 min | 48 min |
| Bulk fermentation with stretch-and-folds3–4 sets of folds in the first ~2 hours, then leave it to rise | 3.5 h | 4.3 h |
| Pre-shape & bench rest | 24 min | 4.7 h |
| Final shape | 12 min | 4.8 h |
| Cold retard (refrigerator)develops flavour + firms the dough for scoring | 8 h | 12.8 h |
| Bake — 475°F in a dutch ovenabout 40 minutes | 42 min | 13.5 h |
A sample overnight clock plan
One realistic way to fit 40% Rye Hearth Loaf around a normal day, at ~76°F. Shift the whole thing earlier or later to suit — only the gaps between stages matter.
- 12:00 PM — feed the levain (peaks in ~5 h).
- 5:00 PM — Autolyse.
- 5:30 PM — Mix.
- 5:45 PM — Bulk fermentation with stretch-and-folds.
- 9:15 PM — Pre-shape & bench rest.
- 9:39 PM — Final shape.
- 9:48 PM — Cold retard.
- 5:48 AM — Bake.
- 6:28 AM — loaf out of the oven; cool at least 1 hour before slicing.
Reading each stage by feel
The clock is a guide; the dough is the real timer. Levain is ready at its peak — domed and just starting to recede, floating in water. Bulk is done at a 50–75% rise with a bubbly, jiggly, domed mass — under-shooting gives a tight crumb, over-shooting a slack, gummy one. Proof is judged by the poke test: a slow, partial spring-back. Because 40% Rye Hearth Loaf cold-retards, you can bake straight from the fridge — cold dough scores more cleanly.
Temperature × time table
| Kitchen temp | Multiplier | Bulk (h) | Proof (h) |
|---|---|---|---|
| 62°F | 2.20× | 7.7 | 17.6 |
| 68°F | 1.58× | 5.5 | 12.6 |
| 72°F | 1.23× | 4.3 | 9.8 |
| 76°F | 1.00× | 3.5 | 8.0 |
| 80°F | 0.78× | 2.7 | 6.2 |
| 85°F | 0.56× | 2.0 | 4.5 |
Calculator pre-set to 40% Rye Hearth Loaf
- Multiplier at 76°F
- 1×
- Adjusted bulk ferment
- 3.5 h
- Adjusted final proof
- 8 h
How the math works
Multipliers are piecewise-linear interpolations between reference points measured by Myhrvold et al. in Modernist Bread vol 3. 76°F is the baseline (1.0×); every 10°F drop roughly doubles fermentation time, and every 10°F rise roughly halves it.
40% Rye Hearth Loaf timing — FAQ
How long does 40% Rye Hearth Loaf take start to finish?
Plan on a ~5-hour levain build first, then about 13.5 h of dough-day work at a 76°F baseline — most of which is a hands-off 8 h cold retard in the refrigerator, so active time is only ~5.5 h. Warmer kitchens run faster and cooler ones slower; use the temperature table below to re-time every stage.
How long is the 40% Rye Hearth Loaf bulk ferment?
3.5 h at 76°F. It's done when the dough has risen 50–75%, domed, and jiggles when you shake the container — not strictly at the 3.5 h mark. Multiply by your kitchen's temperature factor (table below) to re-time it.
Can I bake 40% Rye Hearth Loaf the same day instead of cold-retarding?
Yes — replace the 8 h refrigerator retard with a 1.5 h–2.5 h room-temperature proof and bake once a floured poke springs back slowly and only partway. You trade some flavour depth and scoring ease for speed.
When is 40% Rye Hearth Loaf fully proofed and ready to bake?
Use the poke test: flour a finger, press ~1 cm into the shaped loaf. Ready dough springs back slowly and only partway, leaving a slight dent. Instant spring-back = under-proofed (give it more time); no spring-back and a dense feel = over-proofed (bake immediately, next time shorten the proof).