Convert 6g (2 tsp) Instant Dry Yeast to Sourdough Starter (500g Flour Recipe)
Zero-drift flour and liquid deduction math for converting 6g of instant dry yeast into 50%–125% hydration sourdough levain on a 500g base.
There are two defensible answers to this conversion, and the difference matters. Packet-equivalency treats 6g of Instant Dry Yeast as a fixed quantity of leavening power, so you need 85.7g of ripe starter and must remove 42.9g flour plus 42.9g water from the 500g base. Baker's math instead standardises on 20% inoculation, giving 100g of starter on the same 500g flour with 450g flour and 300g liquid left in the bowl.
- Direct Yeast Equivalent
- 85.7g StarterDeduct 42.9g flour & 42.9g 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
Yeast-to-Sourdough Conversion Table: 6g Instant Dry Yeast on a 500g Base
Starter hydration shifts the deduction asymmetrically: a stiffer levain carries more flour and less water per gram.
| Starter Hydration | Packet-Equivalent Starter (Deductions) | Adjusted Main Dough (Packet Mode) | 20% Artisan Starter (Deductions) | Adjusted Main Dough (20% Mode) |
|---|---|---|---|---|
| 500g flour @ 75% [Baseline] | 85.7g starter (49g F / 36.7g W) | 451g F / 313.3g W | 100g starter (57.1g F / 42.9g W) | 442.9g F / 307.1g W |
| 1000g flour @ 100% Stiffer Starter | 85.7g starter (42.9g F / 42.9g W) | 957.1g F / 657.1g W | 200g starter (100g F / 100g W) | 900g F / 600g W |
| 400g flour @ 125% Wetter Starter | 85.7g starter (38.1g F / 47.6g W) | 361.9g F / 232.4g W | 80g starter (35.6g F / 44.4g W) | 364.4g F / 235.6g W |
| 500g flour @ 50% Lighter Starter | 85.7g starter (57.1g F / 28.6g W) | 442.9g F / 321.4g W | 100g starter (66.7g F / 33.3g W) | 433.3g F / 316.7g W |
| 500g flour @ 100% Heavier Starter | 85.7g starter (42.9g F / 42.9g W) | 457.1g F / 307.1g W | 100g starter (50g F / 50g W) | 450g F / 300g W |
Custom Batch Recalculation Engine
Fine-tune starter hydration between 50% stiff and 125% liquid while keeping your yeast ↔ sourdough conversion ratios locked.
Why 6g Instant Dry Yeast Cannot Be Swapped in 500g Flour Without Deducting Starter Water
Hydration drift is the most common way this conversion goes wrong. Adding 85.7g of levain to 500g flour and 350g water without the 42.9g deduction pushes the dough to 72.4% true hydration, and the extra free water is exactly what turns a slack dough into a puddle.
Keep a log. The most useful column is not the culture weight but the total elapsed time from mixing to shaping, because on the second and third bake the 500g formula with 85.7g of levain is a different dough to the one you remember.
3-Step Conversion Checklist (6g Instant Dry Yeast → Sourdough in 500g Flour)
- Calculate the Deduction First: 85.7g of starter carries 42.9g of flour and 42.9g of water, so write those two numbers on your bench sheet before you open the flour bag.
- Build the 500g Base: Use 457.1g flour and 307.1g liquid, which keeps the dough at 70% true hydration.
- Incorporate 85.7g of Starter: Dimple in the sourdough culture 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.
Technical Q&A: Convert 6g (2 tsp) Instant Dry Yeast to Sourdoug
How much longer does sourdough take to rise than 6g of Instant Dry Yeast?
Expect bulk fermentation on a 500g flour batch to take 4.0 – 5.5 hours at 76°F (24°C), roughly 3 to 4 times longer than commercial instant dry yeast.
How do I convert a sweet or enriched recipe with 6g of Instant 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.
Why does my converted 500g dough feel stickier than the original?
Almost always the 42.9g of hidden starter water was not deducted. Correct the liquid to 307.1g and the dough will tighten immediately.