Converting High-Yeast 14g (2 Packets) Fresh Cake Yeast to Sourdough Levain in 500g Flour
High-inoculation conversion math comparing 66.7g direct yeast equivalency vs. 100g (20% baker's math) for 500g flour recipes.
There are two defensible answers to this conversion, and the difference matters. Packet-equivalency treats 14g of Fresh Cake Yeast as a fixed quantity of leavening power, so you need 66.7g of ripe starter and must remove 33.3g flour plus 33.3g 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
- 66.7g StarterDeduct 33.3g flour & 33.3g 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
Hidden Flour & Water Inside the Levain (14g Fresh Cake Yeast → 500g 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 |
|---|---|---|---|---|
| [Baseline]: 400g / 75% | hidden 38.1g F + 28.6g W | → 361.9g / 251.4g | hidden 45.7g F + 34.3g W | → 354.3g / 245.7g |
| Stiffer Starter: 500g / 100% | hidden 33.3g F + 33.3g W | → 466.7g / 316.7g | hidden 50g F + 50g W | → 450g / 300g |
| Wetter Starter: 500g / 125% | hidden 29.6g F + 37g W | → 470.4g / 313g | hidden 44.4g F + 55.6g W | → 455.6g / 294.4g |
| Lighter Starter: 1000g / 50% | hidden 44.4g F + 22.2g W | → 955.6g / 677.8g | hidden 133.3g F + 66.7g W | → 866.7g / 633.3g |
| Heavier Starter: 500g / 100% | hidden 33.3g F + 33.3g W | → 466.7g / 316.7g | hidden 50g F + 50g W | → 450g / 300g |
Interactive Yeast ↔ Sourdough Conversion Calculator
Compare your exact mixing bowl dimensions, flour protein percentage, or discard weight in real time.
Balancing Osmotic Stress & Hydration When Replacing 14g Fresh Cake Yeast in 500g Flour
The conversion factor between fresh cake yeast and levain is fixed by the packet anchor rather than by the flour. 14g of dry yeast normalises to 66.7g of culture, and the 33.3g of flour and 33.3g of water inside it must be taken back out of the 500g base before the true hydration holds.
Timing is the practical difference. A 500g dough raised with 14g of fresh cake yeast would be ready in ninety minutes, while the same dough carrying 100g of levain 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 (14g Fresh Cake Yeast → Sourdough in 500g Flour)
- Prepare the Levain Ahead: Build 100g of ripe 100% hydration culture and feed it early enough that it domes before you mix the 500g dough.
- Mix Flour and Liquid (450g + 300g): Combine the adjusted flour and liquid, reserving 10% of the water for the salt.
- Add Starter and Salt: Work in 100g of levain plus 2% salt, then perform 4 sets of stretch and coil folds at 30-minute intervals.
- Bulk to +50% and Shape: Let the 500g batch rise to the target aliquot volume, preshape, bench rest 20 minutes, and shape before a long cold retard.
Frequently Asked Questions for This Yeast ↔ Sourdough Conversion Spec
How much longer does sourdough take to rise than 14g of Fresh Cake 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 fresh cake yeast.
Is a 500g sourdough conversion suitable for a pizza or focaccia base?
Yes, and long cold retarding is often an advantage for pizza. Mix 100g of levain into 450g flour and 300g water and refrigerate 24–48 hours.
Should I use 66.7g or 100g of starter?
Use 66.7g if you want to preserve the exact leavening power of 14g fresh cake yeast. Use 100g if you want standard 20% artisan inoculation regardless of the original yeast weight.