Convert 5g (1⅔ tsp) Active Dry Yeast to Sourdough Starter (400g Flour Recipe)
Zero-drift flour and liquid deduction math for converting 5g of active dry yeast into 50%–125% hydration sourdough levain on a 400g base.
If your goal is simply a sourdough version of a 400g recipe that used 5g of Active Dry Yeast, the simplest path is 20% inoculation: 80g of ripe levain, with 40g flour and 40g water removed from the main mix, leaving 360g and 240g. Expect 4.0 – 5.5 hours at 76°F (24°C) instead of a two-hour rise.
- Direct Yeast Equivalent
- 57.1g StarterDeduct 28.6g flour & 28.6g 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
Starter Deduction Grid for 5g (1⅔ tsp) Active Dry Yeast in 400g Flour
Exact starter weights and main dough flour/water deductions for 5g Active Dry Yeast in 400g flour so True Total Hydration never drifts.
| Starter Hydration Level | Levain Required by Yeast Weight | Flour & Liquid Left in the Bowl | Levain Required at 20% Inoculation | Corrected Main Mix |
|---|---|---|---|---|
| Line 400g at 100% [Your Formula] | packet 57.1g (deduct 28.6g/28.6g) | remaining 371.4g + 251.4g | artisan 80g (deduct 40g/40g) | remaining 360g + 240g |
| Line 400g at 125% Leaner Dough | packet 57.1g (deduct 25.4g/31.7g) | remaining 374.6g + 248.3g | artisan 80g (deduct 35.6g/44.4g) | remaining 364.4g + 235.6g |
| Line 500g at 50% Wetter Dough | packet 57.1g (deduct 38.1g/19g) | remaining 461.9g + 331g | artisan 100g (deduct 66.7g/33.3g) | remaining 433.3g + 316.7g |
| Line 1000g at 100% Tighter Dough | packet 57.1g (deduct 28.6g/28.6g) | remaining 971.4g + 671.4g | artisan 200g (deduct 100g/100g) | remaining 900g + 600g |
| Line 400g at 75% Looser Dough | packet 57.1g (deduct 32.7g/24.5g) | remaining 367.3g + 255.5g | artisan 80g (deduct 45.7g/34.3g) | remaining 354.3g + 245.7g |
Dynamic Stoichiometric Workbench (57.1g Starter)
Test custom loaf weights or alternative fermentation schedules directly against the 80g Starter benchmark above.
Why 5g Active Dry Yeast Cannot Be Swapped in 400g Flour Without Deducting Starter Water
Hydration drift is the most common way this conversion goes wrong. Adding 57.1g of levain to 400g flour and 280g water without the 28.6g deduction pushes the dough to 72.0% true hydration, and the extra free water is exactly what turns a slack dough into a puddle.
Timing is the practical difference. A 400g dough raised with 5g of active dry yeast would be ready in ninety minutes, while the same dough carrying 80g of sourdough culture needs 4.0 – 5.5 hours at 76°F (24°C) and a long cold retard to develop the same flavour depth.
3-Step Conversion Checklist (5g Active Dry Yeast → Sourdough in 400g Flour)
- Check the Starter Is Ripe: 80g of levain must be domed, bubbly and at full stretch; a flat starter slows the 4.0 – 5.5 hours at 76°F (24°C) window significantly.
- Combine 400g of Flour with the Adjusted Liquid: Pour 240g, saving 10% to dissolve the salt later.
- Fold in 80g Starter and 2% Salt: Add the levain, pinch through the dough, and work in the salt water.
- Ferment to +50%: Judge by volume in a straight-sided jar, then shape, retard overnight and bake on a preheated stone or in a Dutch oven.
Key Baker's Math Questions (Direct Yeast Equivalent: 57.1g Starter)
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 5g of leavening power is counted. Then deduct 28.6g flour and 28.6g water for the levain you are adding.
Is a 400g sourdough conversion suitable for a pizza or focaccia base?
Yes, and long cold retarding is often an advantage for pizza. Mix 80g of levain into 360g flour and 240g water and refrigerate 24–48 hours.
How much flour and water do I subtract when adding 80g starter to 400g flour?
At 100% starter hydration, subtract 40g flour and 40g water/milk from your 400g flour recipe (leaving 360g flour and 240g liquid).