Temperature × recipe

Sourdough Brioche at 8387°F

Adjusted timing: 1.1h bulk + 1.1h proof (multiplier 0.56×).

Baseline bulk (76°F)
2h
Adjusted bulk
1.1h
Baseline proof
2h
Adjusted proof
1.1h
Multiplier
0.56×
Activity
hyperactive
Target hydration
55%
Bake temp
375°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 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 85°F
0.56×
Adjusted bulk ferment
1.1 h
Adjusted final proof
1.1 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.