Temperature × recipe

Sourdough Brioche at 6367°F

Adjusted timing: 3.8h bulk + 3.8h proof (multiplier 1.90×).

Baseline bulk (76°F)
2h
Adjusted bulk
3.8h
Baseline proof
2h
Adjusted proof
3.8h
Multiplier
1.90×
Activity
moderate
Target hydration
55%
Bake temp
375°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 Sourdough Brioche

Stand mixer mandatory. Combine flour, eggs, levain, salt, sugar in mixer. Knead 5 min on medium. Gradually add softened butter 1 tbsp at a time over 10 min. Knead until window-pane. 2h bulk at 76°F with 2 folds. Shape into log, loaf pan, or braided brioche mold. Cold retard overnight (12-16h at 38°F). Bake from cold at 375°F until internal 195°F (~35 min). Egg wash before bake for shine.

Calculator pre-set to these values

Multiplier at 65°F
1.9×
Adjusted bulk ferment
3.8 h
Adjusted final proof
3.8 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., Brioche formula adapted for sourdough.