Convert 5g (1⅔ tsp) Instant Dry Yeast to Sourdough Starter (500g Flour Recipe)
Zero-drift flour and liquid deduction math for converting 5g of instant dry yeast into 50%–125% hydration sourdough levain on a 500g base.
If your goal is simply a sourdough version of a 500g recipe that used 5g of Instant Dry Yeast, the simplest path is 20% inoculation: 100g of ripe levain, with 50g flour and 50g water removed from the main mix, leaving 450g and 300g. Expect 4.0 – 5.5 hours at 76°F (24°C) instead of a two-hour rise.
- Direct Yeast Equivalent
- 71.4g StarterDeduct 35.7g flour & 35.7g 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
Gram Weights for 500g Flour Sourdough Built from 5g Instant Dry Yeast
Every figure is derived from the 500g flour / 350g liquid base formula and the 5g instant dry yeast dose.
| Starter Water Ratio | Starter Weight & Hidden Flour/Water | Corrected Flour / Corrected Liquid | 20% Inoculation Weight | Corrected Flour / Corrected Liquid |
|---|---|---|---|---|
| 75% starter on 1000g [Exact Target] | packet mode 71.4g | main 959.2g / 669.4g | 20% mode 200g | main 885.7g / 614.3g |
| 100% starter on 400g Alt Row A | packet mode 71.4g | main 364.3g / 244.3g | 20% mode 80g | main 360g / 240g |
| 125% starter on 500g Alt Row B | packet mode 71.4g | main 468.3g / 310.3g | 20% mode 100g | main 455.6g / 294.4g |
| 50% starter on 500g Alt Row C | packet mode 71.4g | main 452.4g / 326.2g | 20% mode 100g | main 433.3g / 316.7g |
| 100% starter on 500g Alt Row D | packet mode 71.4g | main 464.3g / 314.3g | 20% mode 100g | main 450g / 300g |
Interactive Yeast ↔ Sourdough Conversion Calculator
Compare your exact mixing bowl dimensions, flour protein percentage, or discard weight in real time.
Why 5g Instant Dry Yeast Cannot Be Swapped in 500g Flour Without Deducting Starter Water
The instant 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.
Judge the conversion on the dough, not on the scale. The dough should feel the same slackness it had with the original 5g of instant dry yeast, dome predictably, and hold its shape at shaping. If it is spreading, the 35.7g of hidden culture water was not deducted.
3-Step Conversion Checklist (5g Instant Dry Yeast → Sourdough in 500g Flour)
- Calculate the Deduction First: 71.4g of starter carries 35.7g of flour and 35.7g of water, so write those two numbers on your bench sheet before you open the flour bag.
- Build the 500g Base: Use 464.3g flour and 314.3g liquid, which keeps the dough at 70% true hydration.
- Incorporate 71.4g 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.
Frequently Asked Questions for This Yeast ↔ Sourdough Conversion Spec
Does converting to sourdough change the dough weight?
Yes, slightly. The 500g flour and 350g liquid original carried 5 g of dry yeast; the levain version carries 71.4g of starter instead, so expect a small shift in finished loaf weight.
Can I halve the recipe and still use 5g of Instant Dry Yeast?
You can, but the effective inoculation doubles, so 71.4g of levain on half the flour ferments faster than the original. Plan for a shorter bulk.
Can I halve the recipe and still use 5g of Instant Dry Yeast?
You can, but the effective inoculation doubles, so 71.4g of levain on half the flour ferments faster than the original. Plan for a shorter bulk.