How long is the bulk ferment for Sourdough Panettone at 63-67°F?

5.7 hours (3h baseline at 76°F × 1.90 multiplier).

How long is the final proof for Sourdough Panettone at 63-67°F?

19.0 hours (10h baseline at 76°F × 1.90 multiplier).

Temperature × recipe

Sourdough Panettone at 63–67°F

Adjusted timing: 5.7h bulk + 19.0h proof (multiplier 1.90×).

Baseline bulk (76°F): 3h
Adjusted bulk: 5.7h
Baseline proof: 10h
Adjusted proof: 19.0h
Multiplier: 1.90×
Activity: moderate
Target hydration: 50%
Bake temp: 330°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 Panettone

Stage 1 dough: flour, water, levain, sugar, egg yolks — develop gluten in mixer 15 min, let ferment 8h. Stage 2: add butter gradually, then candied fruit, raisins, vanilla, zests. Additional 10 min mixing. Short 3h bulk. Shape into ball, place in panettone mold. Proof 10-12h until dome rises 1 inch above rim. Cut cross in top with butter, bake 330°F for 50-55 min until internal 208°F. Immediately invert, cool hanging upside-down for 4+ hours (prevents compression).

Calculator pre-set to these values

Bulk (at 76°F)(h)

Proof (at 76°F)(h)

Your kitchen temp(°F)

Multiplier at 65°F: 1.9×
Adjusted bulk ferment: 5.7 h
Adjusted final proof: 19 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.