Temperature × recipe

Sourdough Brioche at 5862°F

Adjusted timing: 5.1h bulk + 5.1h proof (multiplier 2.55×).

Baseline bulk (76°F)
2h
Adjusted bulk
5.1h
Baseline proof
2h
Adjusted proof
5.1h
Multiplier
2.55×
Activity
sluggish
Target hydration
55%
Bake temp
375°F

Why the timing shifts

Cold kitchen territory — cellars, garages, unheated rooms. Ferment time is 2.5× longer than baseline 76°F. Excellent for flavor development when you have the patience. If your kitchen runs this cold naturally, either move dough to a warmer spot or extend bulk and proof times dramatically. Consider using 20-25% levain instead of 15-20% to compensate for slow activity.

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 60°F
2.55×
Adjusted bulk ferment
5.1 h
Adjusted final proof
5.1 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.