Sourdough Bulk Fermentation Time at 73 Degrees (73°F / 23°C) with 15% Starter (+60.8% Rise)
Sloped-bowl frustum geometry at 73°F (22.8°C) and 15% inoculation: 34-min coil fold intervals and +60.8% cold-retard cutoff.
A 15% starter build (75g levain) held at 73°F (22.8°C) matures in 6.4–8.1 hours when strengthened at 34-minute intervals. Transfer to cold proof at +60.8% true volumetric expansion (+45.7% vertical height rise in a sloped bowl, or 5.83 cm); doubling vertical height produces a destructive +83.2% volume explosion.
- Estimated Bulk Time
- 6.4–8.1 hrsAt 73°F (22.8°C) with 15% starter (Q10=0.86x)
- Target Aliquot Volume Rise
- +60.8%Capped volumetric cutoff (<44.6°F dormancy)
- Sloped Bowl Height Target
- 5.83 cm+45.7% vertical climb from 4.0 cm
- 2x Height Trap Warning
- +83.2% VolCoil fold every 34m (LAB 5.1:1)
Conical Height vs. Aliquot Volume Matrix Centered on 73°F / 15% Starter
5-point neighborhood comparison around 73°F (22.8°C) and 15% starter (75g/500g flour), showing window hours, conical height rise %, straight-wall volume rise %, and 34-min coil fold intervals.
| Temp & Levain Seed (Around 73°F / 15%) | Fermentation Window | 9" Conical Height Rise | Straight-Wall Volume Rise | Coil Fold Cadence |
|---|---|---|---|---|
| 71°F (21.7°C) @ 13% (65g) Cooler / Lower Seed | 8.3–10.4 hrs (498–624m) | +52% height (4.0 → 6.08 cm) | +70% vol (2x trap: +97.4%) | Every 37 min (Row 1) |
| 73°F (22.8°C) @ 13% (65g) Baseline Temp / Lower Seed | 7.1–9 hrs (426–540m) | +45.9% height (4.0 → 5.84 cm) | +61.1% vol (2x trap: +83.6%) | Every 35 min (Row 2) |
| 73°F (22.8°C) @ 15% (75g) [Current Target] | 6.4–8.1 hrs (384–486m) | +45.7% height (4.0 → 5.83 cm) | +60.8% vol (2x trap: +83.2%) | Every 34 min (Row 3) |
| 73°F (22.8°C) @ 18% (90g) Baseline Temp / Higher Seed | 5.6–7 hrs (336–420m) | +45.4% height (4.0 → 5.82 cm) | +60.3% vol (2x trap: +82.4%) | Every 33 min (Row 4) |
| 75°F (23.9°C) @ 18% (90g) Warmer / Higher Seed | 4.9–6 hrs (294–360m) | +38.3% height (4.0 → 5.53 cm) | +50.2% vol (2x trap: +67.3%) | Every 30 min (Row 5) |
Live Parameter Solver for Sourdough Bulk Fermentation Time at 73 Deg
Dial in custom baker's percentages and export your adjusted 6.4–8.1 hrs formula for bake day.
When to Stop Bulk Fermentation at 73 Degrees (73°F / 23°C): Target +60.8% Rise
Rheological creep-recovery tests at 73°F (22.8°C) show that 15% inoculation softens the gliadin-glutenin network after 6.4–8.1 hours as organic acids accumulate (5.1:1 ratio). Arresting bulk fermentation at 5.83 cm (+45.7% height / +60.8% volume) with 34-minute folds prevents the +83.2% frustum trap.
Conductive heat transfer from a 73°F (22.8°C) boule in a rattan banneton requires hours to reach the 44.6°F yeast-dormancy threshold. During that cooling tail, a 15% inoculation (LAB ratio 5.1:1, Q10=0.86x) adds residual lift—making the +60.8% cutoff (5.83 cm height, 34-min folds) mandatory.
Managing a 73°F (22.8°C) / 15% Inoculation Sourdough Schedule
- Thermal & Levain Calibration (73°F @ 15%): Blend 75g peaked levain into 500g flour at 73°F (22.8°C) to initiate the 6.4–8.1 hr fermentation clock.
- Lamination & 34-Min Folds: Strengthen gluten sheets every 34 minutes as LAB fermentation develops a 5.1:1 organic acid ratio.
- Volumetric vs. Linear Check (+60.8% / 5.83 cm): Call bulk complete at +60.8% aliquot expansion (+45.7% bowl height), bypassing the +83.2% doubling trap.
- Rapid Chilling Protocol (44.6°F Threshold): Stitch tightly in a breathable banneton and chill at 38°F (3.3°C) until core temperature falls below 44.6°F.
Cereal Chemistry & Bench Execution FAQs
Can I cold-retard a 73°F (15% starter) dough for 16 hours after bulk?
Yes—provided you terminate bench fermentation at +60.8% true volumetric expansion (5.83 cm sloped height) after 6.4–8.1 hrs so thermal carryover to 44.6°F does not overproof the gluten.
What percentage rise should I look for at 73°F (22.8°C) with 15% levain?
Target +60.8% true volumetric expansion (+45.7% vertical height rise in a sloped bowl, from 4.0 cm to 5.83 cm) before 38°F cold retarding, avoiding the +83.2% volume explosion of doubling height.
Why is the recommended rise capped at +60.8% for 73°F and 15% starter?
Capping bench expansion at +60.8% true volumetric expansion (+45.7% vertical height rise in a sloped bowl) preserves glutenin elasticity against protease clipping (Q10=0.86x) and avoids a +83.2% volume explosion.