gkwa When to use
Use this when evaluating a sourdough recipe against Tom Cucuzza's two-factor bulk fermentation method, which ends bulk fermentation at a target percentage rise chosen from the dough temperature.
The recipe is supplied as a URL to fetch or as pasted recipe text.
Context to read first
These vault notes hold the framework and a worked example.
Read them before answering.
- /Users/mtm/Documents/Obsidian Vault/When Tom's Percentage Rise Method Does Not Apply, Illustrated by Ciabatta.md for the failure modes and the four-question checklist.
- /Users/mtm/Documents/Obsidian Vault/tom's method on enriched chocolate sourdough.md for a worked example of the fat-and-inclusions failure mode and how the error direction is derived.
Tom's source PDF is the original method, with periodic updates and fuller explanation:
The chart and baseline
These values are reproduced from Tom's PDF so the skill does not depend on fetching it.
Target percentage rise by dough temperature, assuming a cold retard:
| Dough temperature | Target rise | Approx bulk time |
|---|---|---|
| 80°F / 27°C | 30% | 3-5.5 hours |
| 75°F / 24°C | 50% | 5-7 hours |
| 70°F / 21°C | 75% | 8-12 hours |
| 65°F / 18°C | 100% | 12-18 hours |
The clock times are illustrative only; cut bulk on the rise, not the time.
Calibration baseline, Tartine Country Bread:
- 90% bread flour and 10% whole wheat flour
- 75% hydration
- 20% starter
- 2% salt
- about 12.5% protein bread flour, such as King Arthur Bread Flour
- a 30-minute bench rest between pre-shape and final shape
- a cold retard at 37-39°F / 4°C for 8-16 hours
Adjusting the target rise for flour:
- High-protein flours show the rise more, so move the target up.
- Low-protein flours, around 11.5%, show the rise less, so move the target down.
- Low-gluten flours like einkorn and spelt show the rise less, so move the target down.
- The chart targets sit at the low end of the range, so an imperfect loaf is more likely underproofed than overproofed; calibrate upward in 5-10% steps.
The deciding lens
Tom's chart maps a visible percentage rise to a point in fermentation, calibrated on lean Tartine dough at roughly 12.5% protein bread flour, 75% hydration, no fat, and no inclusions, with a cold retard.
The method applies cleanly only when the new dough shows rise at the same rate per unit of real fermentation as that baseline.
Anything that makes the dough show more rise per unit of fermentation means cutting at the chart percentage will under-ferment, so the target should move up.
Examples are tighter or lower-hydration dough and higher-protein flour.
Anything that makes the dough show less rise per unit of fermentation means cutting at the chart percentage will over-ferment, so the target should move down.
Examples are slack high-hydration white-flour dough, fat, heavy inclusions, low-gluten or low-protein flour, and a ferment split between a warm bulk and a cold finish.
The four-question checklist
- Does bulk fermentation complete during the warm bulk ferment, before any cold retard?
- Does the recipe target an open, irregular crumb?
- Is the flour mostly white bread flour at high hydration, above roughly 78%?
- Does the recipe call for strong gluten development?
A no to any of these means Tom's method does not apply straightforwardly, and you should rely on dough feel, bubble structure, jiggle, and the recipe's own stated endpoint.
What to compute from the recipe
- Flour breakdown by weight and type, and the protein level if known.
- Total hydration, including the water carried in the levain.
- Enrichments and inclusions: fat, sugar, eggs, and heavy add-ins like chips, nuts, or dried fruit.
- Gluten development: how many stretch-and-folds and how aggressive they are.
- Whether there is a cold retard, and whether bulk finishes warm or is split between a warm bulk and the fridge.
What to report
- Whether Tom's method applies cleanly, with the four-question checklist answered.
- If it does not apply cleanly, the direction of the error, over or under, with the mechanism stated in one or two sentences.
- A starting target percentage rise or the cue to watch instead, plus a note to calibrate in 5-10% steps on the next bake.