Temperature reference

83–87°F Sourdough (28.30–30.60°C)

Bulk multiplier: 0.550× · Proof multiplier: 0.550× · Activity: hyperactive

Recommendation

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).

Timing calculator at this temperature

Multiplier at 85°F
0.56×
Adjusted bulk ferment
2.2 h
Adjusted final proof
6.7 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.

How each style behaves at this temperature

Click any style to see its full timing at 83–87°F: