Temperature × recipe

40% Rye Hearth Loaf at 6367°F

Adjusted timing: 6.7h bulk + 15.2h proof (multiplier 1.90×).

Baseline bulk (76°F)
3.5h
Adjusted bulk
6.7h
Baseline proof
8h
Adjusted proof
15.2h
Multiplier
1.90×
Activity
moderate
Target hydration
78%
Bake temp
475°F

Why the timing shifts

Cool kitchen — spring/fall without heating, air-conditioned summer. Ferment 1.5× longer than baseline. Good flavor development territory. Dough develops more complex sour notes. Manageable schedule. Extend bulk and proof by 50% vs recipe defaults.

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 65°F
1.9×
Adjusted bulk ferment
6.7 h
Adjusted final proof
15.2 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.

Sources: Myhrvold, Modernist Bread vol 3 (temperature multipliers); Hamelman — Bread 3rd ed., 40% Rye formula.