How to Replace 2g (⅔ tsp) Active Dry Yeast with Sourdough Starter in a 500g Flour Recipe
Zero-drift flour and water deduction guide for converting low-yeast (2g active dry yeast) artisan or poolish doughs into 100g sourdough levain.
To replace 2 g of Active Dry Yeast in a 500g flour recipe (at 70% hydration / 350g liquid), use either: (1) Direct yeast equivalency (22.9g of 100% starter, deducting 11.4g flour and 11.4g liquid to leave 488.6g flour and 338.6g water); or (2) Standard 20% artisan inoculation (100g starter, leaving 450g flour and 300g water at 70% True Hydration).
- Direct Yeast Equivalent
- 22.9g StarterDeduct 11.4g flour & 11.4g water
- 20% Artisan Inoculation
- 100g StarterDeduct 50g flour & 50g water
- Adjusted Main Flour/Water
- 450g / 300gPreserves 500g total system flour at 20% levain
- Sourdough Bulk Window
- 4.0 – 5.5 hoursAt 76°F (24°C) vs. 1–1.5 hrs for commercial yeast
Replacing 2g Active Dry Yeast in 500g Flour Across 50% to 125% Starter Hydrations
Every figure is derived from the 500g flour / 350g liquid base formula and the 2g active dry yeast dose.
| Levain Hydration % | Packet Mode Starter & Deductions | Packet Mode Main Mix | 20% Mode Starter & Deductions | 20% Mode Main Mix |
|---|---|---|---|---|
| 500g flour @ 75% [Baseline] | 22.9g starter (13.1g F / 9.8g W) | 486.9g F / 340.2g W | 100g starter (57.1g F / 42.9g W) | 442.9g F / 307.1g W |
| 400g flour @ 100% Stiffer Starter | 22.9g starter (11.4g F / 11.4g W) | 388.6g F / 268.6g W | 80g starter (40g F / 40g W) | 360g F / 240g W |
| 500g flour @ 125% Wetter Starter | 22.9g starter (10.2g F / 12.7g W) | 489.8g F / 337.3g W | 100g starter (44.4g F / 55.6g W) | 455.6g F / 294.4g W |
| 1000g flour @ 50% Lighter Starter | 22.9g starter (15.2g F / 7.6g W) | 984.8g F / 692.4g W | 200g starter (133.3g F / 66.7g W) | 866.7g F / 633.3g W |
| 500g flour @ 100% Heavier Starter | 22.9g starter (11.4g F / 11.4g W) | 488.6g F / 338.6g W | 100g starter (50g F / 50g W) | 450g F / 300g W |
On-Bench Hydration & Fermentation Adjuster
Modify base flour mass, levain inoculation, or ambient kitchen temperature below to recalculate from this 22.9g Starter baseline.
Replacing Low-Inoculation 2g Active Dry Yeast in 500g Flour Without Shifting Hydration
Flour mass moves too, and bakers tend to forget it. The 11.4g of pre-fermented grain inside 22.9g of levain means the true total grain of your dough is not 500g but 511.4g once the starter is added, which is what makes 70% the correct target rather than the naive 70%.
Direct packet scaling of 2 g (⅔ tsp) Active Dry Yeast maps to 22.9g starter (-11.4g flour / -11.4g water), while artisan baker's math standardises inoculation at 20% of 500g (100g starter, leaving 450g main flour and 300g liquid).
3-Step Conversion Checklist (2g Active Dry Yeast → Sourdough in 500g Flour)
- Scale the Recipe Sheet: Rewrite the original 500g, 350g, 2g active dry yeast formula as 450g flour, 300g liquid, 100g levain and 2% salt.
- Hydrate the Flour: Mix the adjusted flour and 90% of the liquid and rest 45 minutes to fully hydrate the starch.
- Add Levain, Salt and the Last 10%: Work in 100g of starter, 2% salt and the reserved water, then complete the gluten with 3 coil folds.
- Ferment, Shape, Retard: Let the 500g dough reach +50% volume, shape tightly, cold-proof 12–16 hours and bake at 450°F for a blistered crust.
Common Scaling & Troubleshooting Questions (22.9g Starter)
Will my 500g sourdough version rise the same way as the 2 grams active dry yeast original?
No. Sourdough produces gas more slowly and with different gas retention, so judge the converted dough by +50% volumetric rise in a straight-sided jar rather than by doubling in a bowl.
Can I halve the recipe and still use 2g of Active Dry Yeast?
You can, but the effective inoculation doubles, so 22.9g of levain on half the flour ferments faster than the original. Plan for a shorter bulk.
How do I convert a sweet or enriched recipe with 2g of Active Dry Yeast?
The flour and water deduction is identical, but reduce the sugar by about 10%–15%, because the 4.0 – 5.5 hours at 76°F (24°C) sourdough ferment converts more of it than a two-hour commercial rise.