Overnight Counter Sourdough Bulk Fermentation at 66 Degrees (66°F / 19°C) with 8% Starter
Sloped-bowl frustum geometry at 66°F (18.9°C) and 8% inoculation: 44-min coil fold intervals and +75% cold-retard cutoff.
At 66°F (18.9°C) with 8% starter (40g levain per 500g flour), bulk fermentation completes in 16.9–21.9 hours (Q10=0.51x). Cut off bulk at +75% true volumetric expansion (+69.2% vertical height rise in a sloped bowl to 6.77 cm) rather than doubling height, which causes a +140.2% volume explosion.
- Estimated Bulk Time
- 16.9–21.9 hrsAt 66°F (18.9°C) with 8% starter (Q10=0.51x)
- Target Aliquot Volume Rise
- +75%Capped volumetric cutoff (<43.8°F dormancy)
- Sloped Bowl Height Target
- 6.77 cm+69.2% vertical climb from 4.0 cm
- 2x Height Trap Warning
- +140.2% VolCoil fold every 44m (LAB 3.3:1)
Arrhenius Kinetics & Coil-Fold Schedule Matrix Around 66°F (8% Inoculation)
5-point neighborhood comparison around 66°F (18.9°C) and 8% starter (40g/500g flour), showing window hours, conical height rise %, straight-wall volume rise %, and 44-min coil fold intervals.
| Temp & Levain Seed (Around 66°F / 8%) | Fermentation Window | 9" Conical Height Rise | Straight-Wall Volume Rise | Coil Fold Cadence |
|---|---|---|---|---|
| 64°F (17.8°C) @ 6% (30g) Cooler / Lower Seed | 23.9–31.9 hrs (1434–1914m) | +71.7% height (4.0 → 6.87 cm) | +75% vol (2x trap: +146.9%) | Every 47 min (Row 1) |
| 66°F (18.9°C) @ 6% (30g) Baseline Temp / Lower Seed | 21–27.1 hrs (1260–1626m) | +69.5% height (4.0 → 6.78 cm) | +75% vol (2x trap: +141%) | Every 45 min (Row 2) |
| 66°F (18.9°C) @ 8% (40g) [Current Target] | 16.9–21.9 hrs (1014–1314m) | +69.2% height (4.0 → 6.77 cm) | +75% vol (2x trap: +140.2%) | Every 44 min (Row 3) |
| 66°F (18.9°C) @ 11% (55g) Baseline Temp / Higher Seed | 13.3–17.2 hrs (798–1032m) | +68.7% height (4.0 → 6.75 cm) | +75% vol (2x trap: +139%) | Every 43 min (Row 4) |
| 68°F (20°C) @ 11% (55g) Warmer / Higher Seed | 11.7–14.1 hrs (702–846m) | +59.9% height (4.0 → 6.4 cm) | +75% vol (2x trap: +116.3%) | Every 41 min (Row 5) |
Real-Time Dough & Starter Scaling Sandbox
Scale this Overnight Sourdough Bulk Fermentatio specification up or down on your digital scale with zero hydration drift.
Overnight Cold-Counter Kinetics at 66 Degrees (66°F / 19°C): Target +75% Rise
Beta-amylase cleavage of damaged wheat starch supplies maltose to Kazachstania exigua across the 16.9–21.9 hr fermentation at 66°F (18.9°C) (8% starter). Maintaining a 44-minute fold cadence aligns gas cell walls so the matrix captures +75% gas expansion (6.77 cm bowl height) while holding a 3.3:1 acid ratio.
Surface tension generated during shaping at 66°F (18.9°C) must withstand both 8% levain gas pressure and the cooling transition to 43.8°F. By capping bulk at +75% volumetric expansion (6.77 cm / +69.2% height at 16.9–21.9 hrs) with 44-min folds, blisters form cleanly without collapsing.
Step-by-Step 66°F / 8% Starter Execution & 6.77 cm Cutoff
- Starter Dispersion (40g per 500g Flour): Pinch 8% ripe starter into the autolysed mass at 66°F (18.9°C), establishing a 0.51x metabolic rate.
- Scheduled Strengthening (Every 44 Mins): Lift and tuck the dough every 44 minutes to balance the 3.3:1 lactic-to-acetic acid curve.
- Geometric Termination (+75% Volume): End bulk between 16.9 and 21.9 hrs once vertical height reaches 6.77 cm (+69.2%), avoiding the +140.2% 2x-height blowout.
- Cold-Shelf Transfer (43.8°F Cutoff): Seal the shaped loaf in a floured liner and place on the bottom 37°F–38°F fridge shelf to arrest yeast below 43.8°F.
Diagnostic Answers: Overnight Sourdough Bulk Fermentation at 66
What is the Q10 metabolic speed factor at 66°F (18.9°C)?
At 66°F (18.9°C), sourdough yeast and LAB operate at a 0.51x Q10 velocity relative to 75°F, yielding a 3.3:1 lactic-to-acetic acid ratio over 16.9–21.9 hours at 8% starter.
Why is the recommended rise capped at +75% for 66°F and 8% starter?
Capping bench expansion at +75% true volumetric expansion (+69.2% vertical height rise in a sloped bowl) preserves glutenin elasticity against protease clipping (Q10=0.51x) and avoids a +140.2% volume explosion.
At what internal temperature does a 66°F dough stop rising in the fridge?
When transferred from 66°F (18.9°C) to a 38°F refrigerator at +75% volume (6.77 cm bowl height), wild yeast budding tapers into dormancy once the core cools below 43.8°F.