Sourdough Bulk Fermentation Time at 75 Degrees (75°F / 24°C) with 22% Starter (+49.8% Rise)
Thermal carryover modeling into a 38°F retarder from 75°F (23.9°C) at 22% levain: target +38% vertical climb (5.52 cm).
For a 75°F (23.9°C) batch seeded at 22% starter (110g per 500g flour), schedule 4.2–5.1 hours on the bench and fold every 29 minutes. Bench-shape strictly at +49.8% true volumetric expansion (+38% vertical height rise in a sloped bowl to 5.52 cm) so you never suffer the +66.7% volume explosion of doubling bowl height.
- Estimated Bulk Time
- 4.2–5.1 hrsAt 75°F (23.9°C) with 22% starter (Q10=1x)
- Target Aliquot Volume Rise
- +49.8%Capped volumetric cutoff (<44.7°F dormancy)
- Sloped Bowl Height Target
- 5.52 cm+38% vertical climb from 4.0 cm
- 2x Height Trap Warning
- +66.7% VolCoil fold every 29m (LAB 5.8:1)
Conical Height vs. Aliquot Volume Matrix Centered on 75°F / 22% Starter
5-point neighborhood comparison around 75°F (23.9°C) and 22% starter (110g/500g flour), showing window hours, conical height rise %, straight-wall volume rise %, and 29-min coil fold intervals.
| Temp & Levain Seed (Around 75°F / 22%) | Fermentation Window | 9" Conical Height Rise | Straight-Wall Volume Rise | Coil Fold Cadence |
|---|---|---|---|---|
| 73°F (22.8°C) @ 20% (100g) Cooler / Lower Seed | 5.2–6.5 hrs (312–390m) | +45.2% height (4.0 → 5.81 cm) | +60% vol (2x trap: +81.9%) | Every 32 min (Row 1) |
| 75°F (23.9°C) @ 20% (100g) Baseline Temp / Lower Seed | 4.5–5.5 hrs (270–330m) | +38.1% height (4.0 → 5.52 cm) | +50% vol (2x trap: +67%) | Every 30 min (Row 2) |
| 75°F (23.9°C) @ 22% (110g) [Current Target] | 4.2–5.1 hrs (252–306m) | +38% height (4.0 → 5.52 cm) | +49.8% vol (2x trap: +66.7%) | Every 29 min (Row 3) |
| 75°F (23.9°C) @ 25% (125g) Baseline Temp / Higher Seed | 3.8–4.7 hrs (228–282m) | +37.7% height (4.0 → 5.51 cm) | +49.4% vol (2x trap: +66.1%) | Every 28 min (Row 4) |
| 77°F (25°C) @ 25% (125g) Warmer / Higher Seed | 3.2–4.1 hrs (192–246m) | +33% height (4.0 → 5.32 cm) | +42.8% vol (2x trap: +56.6%) | Every 26 min (Row 5) |
Custom Batch Recalculation Engine
Fine-tune starter hydration between 50% stiff and 125% liquid while keeping your bulk fermentation temp × inoculation ratios locked.
When to Stop Bulk Fermentation at 75 Degrees (75°F / 24°C): Target +49.8% Rise
At 75°F (23.9°C), a 22% levain inoculation drives CO2 saturation across a 4.2–5.1 hr kinetic window (Q10=1x). Because a 24 cm sloped bowl widens quadratically with elevation z, a +49.8% volumetric target equals 5.52 cm (+38% height), whereas 8.0 cm height triggers a +66.7% collapse.
According to Henry's Law of gas solubility, chilling a 75°F (23.9°C) dough mass below 44.7°F increases aqueous CO2 absorption into the dough liquor while 22% levain yeast slows down. Shaping at 5.52 cm (+38% conical climb, +49.8% volume) after 4.2–5.1 hrs preserves spring without hitting the +66.7% trap.
Step-by-Step 75°F / 22% Starter Execution & 5.52 cm Cutoff
- Quantitative Weigh-In (22% Seed): Measure 110g bubbly 100% starter into your 500g flour batch and confirm a 75°F (23.9°C) post-mix temperature.
- Timed Coil-Fold Window (29 Mins): Space 3 to 4 coil folds at 29-minute intervals while Q10=1x kinetics build alveolar tension.
- Sloped-Bowl Readout (5.52 cm Target): Watch for domed shoulders at 4.2–5.1 hrs when bowl depth climbs +38% to 5.52 cm (+49.8% true volume).
- Overnight Retardation (<44.7°F): Shape with minimal flour and cold-proof 12–16 hours at 38°F as core temperature crosses the 44.7°F dormancy line.
Technical Q&A: Sourdough Bulk Fermentation Time at 75 Degrees (
How high should dough climb in a 9-inch sloped bowl at 75°F and 22% starter?
Starting at 4.0 cm depth in a 24 cm top / 14 cm bottom bowl, stop bulk at 5.52 cm (+38% vertical height rise in a sloped bowl), which equals +49.8% true volumetric expansion.
What is the Q10 metabolic speed factor at 75°F (23.9°C)?
At 75°F (23.9°C), sourdough yeast and LAB operate at a 1x Q10 velocity relative to 75°F, yielding a 5.8:1 lactic-to-acetic acid ratio over 4.2–5.1 hours at 22% starter.
Should I use an aliquot jar or bowl ruler for 75°F bulk fermentation at 22% levain?
Either works when calibrated: look for +49.8% true volumetric expansion in a straight-walled aliquot jar, or +38% vertical height rise in a sloped bowl (4.0 cm to 5.52 cm) over 4.2–5.1 hrs.