Temperature × recipe

40% Rye Hearth Loaf at 8387°F

Adjusted timing: 2.0h bulk + 4.5h proof (multiplier 0.56×).

Baseline bulk (76°F)
3.5h
Adjusted bulk
2.0h
Baseline proof
8h
Adjusted proof
4.5h
Multiplier
0.56×
Activity
hyperactive
Target hydration
78%
Bake temp
475°F

Why the timing shifts

Hot kitchen — summer without AC, near-window light. Ferment nearly 2× faster than baseline. Not ideal — fermentation outpaces gluten development, leading to over-acidic flavor and collapsed structure. If unavoidable, use very low levain (10-12%), minimal bulk (2h max), and get dough into cold retard ASAP. Consider reducing bulk temperature by moving dough to cooler location (basement, refrigerator brief intervals).

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 85°F
0.56×
Adjusted bulk ferment
2 h
Adjusted final proof
4.5 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.