Fermentation timing

Hokkaido Milk Bread (Sourdough) — Timing by Kitchen Temperature

Baseline: 2.5h bulk + 3h proof at 76°F. Adjust for your kitchen below.

Temperature × time table

Kitchen tempMultiplierBulk (h)Proof (h)
62°F2.20×5.56.6
68°F1.58×3.94.7
72°F1.23×3.13.7
76°F1.00×2.53.0
80°F0.78×2.02.3
85°F0.56×1.41.7

Calculator pre-set to Hokkaido Milk Bread (Sourdough)

Multiplier at 76°F
Adjusted bulk ferment
2.5 h
Adjusted final proof
3 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 et al., Modernist Bread vol 3 (temperature multipliers); Asian bakery tradition; adapted for sourdough per King Arthur.