Temperature × recipe

Country Loaf (Pain de Campagne) at 6872°F

Adjusted timing: 5.4h bulk + 16.2h proof (multiplier 1.35×).

Baseline bulk (76°F)
4h
Adjusted bulk
5.4h
Baseline proof
12h
Adjusted proof
16.2h
Multiplier
1.35×
Activity
moderate
Target hydration
75%
Bake temp
500°F

Why the timing shifts

Most home kitchens — typical year-round room temperature. Ferment slightly longer than 76°F baseline. Recipe times generally work as written with minor extensions (+20%). Good balance of schedule manageability and flavor development. Most Hamelman and Tartine formulas are written assuming this range.

Technique for Country Loaf (Pain de Campagne)

Autolyse 45 min with all flour and 90% of water at 78°F. Add levain (20% of flour weight, 100% hydration), salt, and remaining water. 4 sets of stretch-and-folds in first 2 hours of bulk. Total bulk 4h at 76°F. Preshape round, rest 20 min, final shape tight boule, place in floured banneton. Cold retard 12 hours at 38°F. Bake from cold in 500°F preheated dutch oven: 20 min lid on, 25 min lid off until internal temp 210°F.

Calculator pre-set to these values

Multiplier at 70°F
1.35×
Adjusted bulk ferment
5.4 h
Adjusted final proof
16.2 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); Chad Robertson — Tartine Bread (country loaf formula).