Temperature × recipe

Spelt Hearth Loaf at 6367°F

Adjusted timing: 5.7h bulk + 11.4h proof (multiplier 1.90×).

Baseline bulk (76°F)
3h
Adjusted bulk
5.7h
Baseline proof
6h
Adjusted proof
11.4h
Multiplier
1.90×
Activity
moderate
Target hydration
70%
Bake temp
450°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 Spelt Hearth Loaf

Short autolyse (20 min). 2-3 GENTLE stretch-and-folds (spelt gluten tears easily). 3h bulk. Shape carefully, floured banneton, 6h cold retard. Bake in dutch oven 450°F: 20 min lid on, 18 min off.

Calculator pre-set to these values

Multiplier at 65°F
1.9×
Adjusted bulk ferment
5.7 h
Adjusted final proof
11.4 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); Peter Reinhart — Whole Grain Breads, Spelt chapter.