Overnight Counter Sourdough Bulk Fermentation at 68 Degrees (68°F / 20°C) with 5% Starter
Calibrated 21.2–25.5 hr fermentation window at 68°F (20°C) with 5% levain, targeting +75% volume (+60.7% conical height).
A 5% starter build (25g levain) held at 68°F (20°C) matures in 21.2–25.5 hours when strengthened at 43-minute intervals. Transfer to cold proof at +75% true volumetric expansion (+60.7% vertical height rise in a sloped bowl, or 6.43 cm); doubling vertical height produces a destructive +118.2% volume explosion.
- Estimated Bulk Time
- 21.2–25.5 hrsAt 68°F (20°C) with 5% starter (Q10=0.59x)
- Target Aliquot Volume Rise
- +75%Capped volumetric cutoff (<44.2°F dormancy)
- Sloped Bowl Height Target
- 6.43 cm+60.7% vertical climb from 4.0 cm
- 2x Height Trap Warning
- +118.2% VolCoil fold every 43m (LAB 3.6:1)
Conical Height vs. Aliquot Volume Matrix Centered on 68°F / 5% Starter
5-point neighborhood comparison around 68°F (20°C) and 5% starter (25g/500g flour), showing window hours, conical height rise %, straight-wall volume rise %, and 43-min coil fold intervals.
| Temp & Levain Seed (Around 68°F / 5%) | Fermentation Window | 9" Conical Height Rise | Straight-Wall Volume Rise | Coil Fold Cadence |
|---|---|---|---|---|
| 66°F (18.9°C) @ 3% (15g) Cooler / Lower Seed | 35.2–45.6 hrs (2112–2736m) | +69.6% height (4.0 → 6.78 cm) | +75% vol (2x trap: +141.4%) | Every 46 min (Row 1) |
| 68°F (20°C) @ 3% (15g) Baseline Temp / Lower Seed | 31.1–37.4 hrs (1866–2244m) | +60.7% height (4.0 → 6.43 cm) | +75% vol (2x trap: +118.2%) | Every 44 min (Row 2) |
| 68°F (20°C) @ 5% (25g) [Current Target] | 21.2–25.5 hrs (1272–1530m) | +60.7% height (4.0 → 6.43 cm) | +75% vol (2x trap: +118.2%) | Every 43 min (Row 3) |
| 68°F (20°C) @ 8% (40g) Baseline Temp / Higher Seed | 14.9–17.9 hrs (894–1074m) | +60.3% height (4.0 → 6.41 cm) | +75% vol (2x trap: +117.2%) | Every 42 min (Row 4) |
| 70°F (21.1°C) @ 8% (40g) Warmer / Higher Seed | 12.9–15.9 hrs (774–954m) | +55.2% height (4.0 → 6.21 cm) | +74.7% vol (2x trap: +104.8%) | Every 40 min (Row 5) |
Interactive Bulk Fermentation Temp × Inoculation Calculator
Compare your exact mixing bowl dimensions, flour protein percentage, or discard weight in real time.
Overnight Cold-Counter Kinetics at 68 Degrees (68°F / 20°C): Target +75% Rise
Homofermentative and heterofermentative LAB populations at 68°F (20°C) with 5% starter generate a 3.6:1 lactic-to-acetic molar ratio over 21.2–25.5 hours. As pH drops toward 4.2, spacing coil folds at 43-minute intervals preserves glutenin elasticity until the dough hits +75% volume (+60.7% height at 6.43 cm).
Biot-number thermal gradients inside an 850g–950g batard mean the outer crust chills to 44.2°F long before the 68°F (20°C) center. For a 5% levain formula (Q10=0.59x, 43-min fold spacing), terminating bulk at 21.2–25.5 hrs and 6.43 cm (+60.7% height / +75% volume) prevents center-crumb blowout.
Managing a 68°F (20°C) / 5% Inoculation Sourdough Schedule
- Starter Dispersion (25g per 500g Flour): Pinch 5% ripe starter into the autolysed mass at 68°F (20°C), establishing a 0.59x metabolic rate.
- Scheduled Strengthening (Every 43 Mins): Lift and tuck the dough every 43 minutes to balance the 3.6:1 lactic-to-acetic acid curve.
- Geometric Termination (+75% Volume): End bulk between 21.2 and 25.5 hrs once vertical height reaches 6.43 cm (+60.7%), avoiding the +118.2% 2x-height blowout.
- Cold-Shelf Transfer (44.2°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 44.2°F.
Frequently Asked Questions for This Bulk Fermentation Temp × Inoculation Spec
At what internal temperature does a 68°F dough stop rising in the fridge?
When transferred from 68°F (20°C) to a 38°F refrigerator at +75% volume (6.43 cm bowl height), wild yeast budding tapers into dormancy once the core cools below 44.2°F.
How do I adjust 68°F bulk time if I drop starter from 5% to 3%?
Reducing inoculation from 5% to 3% at 68°F (20°C) extends the 21.2–25.5 hr bulk window while keeping the same +75% volumetric (6.43 cm height) shaping target.
How high should dough climb in a 9-inch sloped bowl at 68°F and 5% starter?
Starting at 4.0 cm depth in a 24 cm top / 14 cm bottom bowl, stop bulk at 6.43 cm (+60.7% vertical height rise in a sloped bowl), which equals +75% true volumetric expansion.