Fermentation timing
Spelt Hearth Loaf — Timing by Kitchen Temperature
Baseline: 3h bulk + 6h proof at 76°F. Adjust for your kitchen below.
The full Spelt Hearth Loaf schedule (76°F baseline)
Spelt Hearth Loaf is a hearth-style sourdough from Germany/Switzerland. From a ripe levain to a cooled loaf it runs about 10.9 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 h | 3.8 h |
| Pre-shape & bench rest | 24 min | 4.2 h |
| Final shape | 12 min | 4.3 h |
| Cold retard (refrigerator)develops flavour + firms the dough for scoring | 6 h | 10.3 h |
| Bake — 450°F in a dutch ovenabout 38 minutes | 36 min | 10.9 h |
A sample overnight clock plan
One realistic way to fit Spelt 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.
- 8:45 PM — Pre-shape & bench rest.
- 9:09 PM — Final shape.
- 9:18 PM — Cold retard.
- 3:18 AM — Bake.
- 3:56 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 Spelt 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× | 6.6 | 13.2 |
| 68°F | 1.58× | 4.7 | 9.5 |
| 72°F | 1.23× | 3.7 | 7.4 |
| 76°F | 1.00× | 3.0 | 6.0 |
| 80°F | 0.78× | 2.3 | 4.7 |
| 85°F | 0.56× | 1.7 | 3.4 |
Calculator pre-set to Spelt Hearth Loaf
- Multiplier at 76°F
- 1×
- Adjusted bulk ferment
- 3 h
- Adjusted final proof
- 6 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.
Spelt Hearth Loaf timing — FAQ
How long does Spelt Hearth Loaf take start to finish?
Plan on a ~5-hour levain build first, then about 10.9 h of dough-day work at a 76°F baseline — most of which is a hands-off 6 h cold retard in the refrigerator, so active time is only ~4.9 h. Warmer kitchens run faster and cooler ones slower; use the temperature table below to re-time every stage.
How long is the Spelt Hearth Loaf bulk ferment?
3 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 h mark. Multiply by your kitchen's temperature factor (table below) to re-time it.
Can I bake Spelt Hearth Loaf the same day instead of cold-retarding?
Yes — replace the 6 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 Spelt 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).