Temperature × recipe
40% Rye Hearth Loaf at 36–40°F
Adjusted timing: 10.2h bulk + 23.2h proof (multiplier 2.90×).
- Baseline bulk (76°F)
- 3.5h
- Adjusted bulk
- 10.2h
- Baseline proof
- 8h
- Adjusted proof
- 23.2h
- Multiplier
- 2.90×
- Activity
- dormant
- Target hydration
- 78%
- Bake temp
- 475°F
Why the timing shifts
Refrigerator territory — used for overnight retard during proofing or bulk slowdown. 12-16 hours at this temperature is equivalent to 1-1.5 hours at 76°F baseline. Essential for flavor development in artisan sourdough. Cold retard improves shape retention, enables flexible scheduling, and develops deeper tangy flavors. Place dough in floured banneton, cover, refrigerate at this temperature.
Technique for 40% Rye Hearth Loaf
Autolyse wheat flours 30 min with water. Add rye flour, levain, salt. Mix thoroughly by hand (rye prevents useful kneading). 3-4 coil folds over 3h bulk at 76°F. Shape in floured banneton. Cold retard 8h. Bake in preheated dutch oven at 475°F: 20 min lid on, 20 min lid off.
Calculator pre-set to these values
- Multiplier at 38°F
- 2.9×
- Adjusted bulk ferment
- 10.2 h
- Adjusted final proof
- 23.2 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.