Convert 6g (2 tsp) Active Dry Yeast to Sourdough Starter (400g Flour Recipe)
Zero-drift flour and liquid deduction math for converting 6g of active dry yeast into 50%–125% hydration sourdough levain on a 400g base.
Start with the mass balance. 6g of active dry yeast contributes no flour and no water to your dough; 68.6g of 100% hydration starter contributes 34.3g of each. So a 400g flour, 280g liquid formula becomes 365.7g flour and 245.7g liquid once the levain goes in, and the dough will ferment on sourdough's clock rather than yeast's.
- Direct Yeast Equivalent
- 68.6g StarterDeduct 34.3g flour & 34.3g water
- 20% Artisan Inoculation
- 80g StarterDeduct 40g flour & 40g water
- Adjusted Main Flour/Water
- 360g / 240gPreserves 400g 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
Hidden Flour & Water Inside the Levain (6g Active Dry Yeast → 400g dough)
Use the 100% hydration row as your working formula unless your levain is deliberately stiff or liquid.
| Hydration of Levain | Yeast-Equivalent Starter | Remaining Main Formula | Baker's-Math Starter | Remaining Main Formula |
|---|---|---|---|---|
| 1000g flour @ 50% [Baseline] | 68.6g starter (45.7g F / 22.9g W) | 954.3g F / 677.1g W | 200g starter (133.3g F / 66.7g W) | 866.7g F / 633.3g W |
| 400g flour @ 100% Stiffer Starter | 68.6g starter (34.3g F / 34.3g W) | 365.7g F / 245.7g W | 80g starter (40g F / 40g W) | 360g F / 240g W |
| 400g flour @ 125% Wetter Starter | 68.6g starter (30.5g F / 38.1g W) | 369.5g F / 241.9g W | 80g starter (35.6g F / 44.4g W) | 364.4g F / 235.6g W |
| 500g flour @ 75% Lighter Starter | 68.6g starter (39.2g F / 29.4g W) | 460.8g F / 320.6g W | 100g starter (57.1g F / 42.9g W) | 442.9g F / 307.1g W |
| 400g flour @ 100% Heavier Starter | 68.6g starter (34.3g F / 34.3g W) | 365.7g F / 245.7g W | 80g starter (40g F / 40g W) | 360g F / 240g W |
Real-Time Dough & Starter Scaling Sandbox
Scale this Convert 6g (2 tsp) Active Dry Yeast specification up or down on your digital scale with zero hydration drift.
Why 6g Active Dry Yeast Cannot Be Swapped in 400g Flour Without Deducting Starter Water
The active dry yeast you are replacing is a single strain with a predictable gas curve, and the levain you are replacing it with is a consortium. That is why 4.0 – 5.5 hours at 76°F (24°C) of fermentation is not simply a slower version of a commercial rise — the flavour, the acid and the extensibility of the finished crumb all change as well.
Proofing structure matters more once you cross over. A levain at 100% hydration is a paste rather than a liquid, so it disperses differently through the 400g of flour than the measured 280g of water it replaces, and the dough usually needs an extra set of folds in the first hour.
3-Step Conversion Checklist (6g Active Dry Yeast → Sourdough in 400g Flour)
- Calculate the Deduction First: 68.6g of starter carries 34.3g of flour and 34.3g of water, so write those two numbers on your bench sheet before you open the flour bag.
- Build the 400g Base: Use 365.7g flour and 245.7g liquid, which keeps the dough at 70% true hydration.
- Incorporate 68.6g of Starter: Dimple in the levain and 2% salt, mix to full cohesion, and rest 30 minutes before the first fold.
- Watch the Aliquot, Not the Clock: Ferment at 75°F until a 30g sample reaches +50% volume, which on sourdough is far more reliable than a timer.
Diagnostic Answers: Convert 6g (2 tsp) Active Dry Yeast to Sourd
How much sourdough culture replaces 6g of Active Dry Yeast in 400g flour?
By direct yeast weight equivalency, 6g of Active Dry Yeast equals 68.6g of 100% hydration sourdough culture. For a 400g flour batch, the 20% baker's inoculation is 80g culture.
Will my 400g sourdough version rise the same way as the 6 g 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 convert a 400g dough that already contains a preferment or poolish?
Yes, but dissolve the preferment's yeast into the main mix first so the full 6g of leavening power is counted. Then deduct 34.3g flour and 34.3g water for the levain you are adding.