Temperature × recipe

Miche (Poilâne-Style) at 8387°F

Adjusted timing: 2.8h bulk + 6.7h proof (multiplier 0.56×).

Baseline bulk (76°F)
5h
Adjusted bulk
2.8h
Baseline proof
12h
Adjusted proof
6.7h
Multiplier
0.56×
Activity
hyperactive
Target hydration
78%
Bake temp
480°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 Miche (Poilâne-Style)

Autolyse 60 min with all water at 80°F. Add levain, salt. 4 folds in 2h. Long bulk 5h at 76°F. Shape very tight boule, heavily flour banneton. Cold retard 12h. Bake in LARGE dutch oven (7-qt minimum) at 480°F: 30 min lid on, 30 min lid off, or until internal 210°F.

Calculator pre-set to these values

Multiplier at 85°F
0.56×
Adjusted bulk ferment
2.8 h
Adjusted final proof
6.7 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); Lionel Poilâne — Pain Poilâne (miche) reference.