Convert 5g (1â tsp) Instant Dry Yeast to Sourdough Starter (1000g Flour Recipe)
Zero-drift flour and liquid deduction math for converting 5g of instant dry yeast into 50%â125% hydration sourdough levain on a 1000g base.
None of the arithmetic changes with the yeast brand, but the type does: instant dry yeast carries its own potency per gram, so 5 grams of it converts to 71.4g of starter rather than the 200g that 20% baker's math prescribes. Either way, deduct the hidden flour and water â 35.7g and 35.7g in packet mode â or the 1000g dough will not hold 70% hydration.
- Direct Yeast Equivalent
- 71.4g StarterDeduct 35.7g flour & 35.7g water
- 20% Artisan Inoculation
- 200g StarterDeduct 100g flour & 100g water
- Adjusted Main Flour/Water
- 900g / 600gPreserves 1000g total system flour at 20% levain
- Sourdough Bulk Window
- 4.0 â 5.5 hoursAt 76°F (24°C) vs. 1â1.5 hrs for commercial yeast
Hidden Flour & Water Inside the Levain (5g Instant Dry Yeast â 1000g 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 |
|---|---|---|---|---|
| Line 1000g at 50% [Your Formula] | packet 71.4g (deduct 47.6g/23.8g) | remaining 952.4g + 676.2g | artisan 200g (deduct 133.3g/66.7g) | remaining 866.7g + 633.3g |
| Line 400g at 100% Leaner Dough | packet 71.4g (deduct 35.7g/35.7g) | remaining 364.3g + 244.3g | artisan 80g (deduct 40g/40g) | remaining 360g + 240g |
| Line 1000g at 125% Wetter Dough | packet 71.4g (deduct 31.7g/39.7g) | remaining 968.3g + 660.3g | artisan 200g (deduct 88.9g/111.1g) | remaining 911.1g + 588.9g |
| Line 500g at 75% Tighter Dough | packet 71.4g (deduct 40.8g/30.6g) | remaining 459.2g + 319.4g | artisan 100g (deduct 57.1g/42.9g) | remaining 442.9g + 307.1g |
| Line 1000g at 100% Looser Dough | packet 71.4g (deduct 35.7g/35.7g) | remaining 964.3g + 664.3g | artisan 200g (deduct 100g/100g) | remaining 900g + 600g |
On-Bench Hydration & Fermentation Adjuster
Modify base flour mass, levain inoculation, or ambient kitchen temperature below to recalculate from this 71.4g Starter baseline.
Why 5g Instant Dry Yeast Cannot Be Swapped in 1000g Flour Without Deducting Starter Water
Scaling the conversion is linear in the flour but not in the yeast. Doubling a 1000g base to 2000g while keeping 5g of Instant Dry Yeast halves the effective inoculation, so 71.4g of sourdough culture is a far gentler ferment than 142.8g would be.
The dough weight of the converted batch is lower than the original. Removing 5 grams of instant dry yeast and adding 71.4g of levain changes the total mass of a 1000g flour dough, which is why the finished loaf bakes slightly differently even though the flour and water balance is identical.
3-Step Conversion Checklist (5g Instant Dry Yeast â Sourdough in 1000g Flour)
- Weigh Active Levain (200g or 71.4g): Measure 200g peaked 100% culture for 20% inoculation, or 71.4g for direct 5g Instant Dry Yeast equivalency.
- Deduct Main Flour & Liquid (1000g Base): Scale main flour to 900g (-100g) and liquid to 600g (-100g).
- Ferment for 4.0 â 5.5 hours at 76°F (24°C): Hold the 1000g dough at 75°Fâ78°F until +50% volumetric expansion before shaping and cold proofing.
- Retard and Bake: Cold-proof the shaped dough for 12â16 hours at 38°F, then bake covered and uncover to a deep mahogany crust.
Common Scaling & Troubleshooting Questions (71.4g Starter)
What salt level should I use on the converted 1000g dough?
Keep 2% of the total system flour, which on a 1000g base with 100g of starter flour is about 22g of salt.
Why does my converted 1000g dough feel stickier than the original?
Almost always the 35.7g of hidden starter water was not deducted. Correct the liquid to 664.3g and the dough will tighten immediately.
Will my 1000g sourdough version rise the same way as the 5 g instant 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.