Temperature × recipe
40% Rye Hearth Loaf at 88–95°F
Adjusted timing: 1.4h bulk + 3.1h proof (multiplier 0.39×).
- Baseline bulk (76°F)
- 3.5h
- Adjusted bulk
- 1.4h
- Baseline proof
- 8h
- Adjusted proof
- 3.1h
- Multiplier
- 0.39×
- Activity
- extreme-mold-risk
- Target hydration
- 78%
- Bake temp
- 475°F
Why the timing shifts
Very hot — avoid. Mold risk rises sharply above 85°F. Fermentation outpaces structural development. Levain becomes unbalanced toward lactic acid producers, creating cloying sour flavor. Only use briefly for refreshing starters or if absolutely unavoidable. Move dough to cooler location, or skip this bake and wait for cooler conditions. If baking must happen, reduce levain to 8%, bulk 90 min max, get into refrigerator immediately after shaping.
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 92°F
- 0.39×
- Adjusted bulk ferment
- 1.4 h
- Adjusted final proof
- 3.1 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.