How to Replace 3g (1 tsp) Fresh Cake Yeast with Sourdough Starter in a 400g Flour Recipe
Zero-drift flour and water deduction guide for converting low-yeast (3g fresh cake yeast) artisan or poolish doughs into 80g sourdough levain.
There are two defensible answers to this conversion, and the difference matters. Packet-equivalency treats 3g of Fresh Cake Yeast as a fixed quantity of leavening power, so you need 14.3g of ripe culture and must remove 7.1g flour plus 7.1g water from the 400g base. Baker's math instead standardises on 20% inoculation, giving 80g of culture on the same 400g flour with 360g flour and 240g liquid left in the bowl.
- Direct Yeast Equivalent
- 14.3g StarterDeduct 7.1g flour & 7.1g 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
Yeast-to-Sourdough Conversion Table: 3g Fresh Cake Yeast on a 400g Base
Use the 100% hydration row as your working formula unless your levain is deliberately stiff or liquid.
| Starter Hydration | Packet-Equivalent Starter (Deductions) | Adjusted Main Dough (Packet Mode) | 20% Artisan Starter (Deductions) | Adjusted Main Dough (20% Mode) |
|---|---|---|---|---|
| [Anchor]: 400g / 75% | hidden 8.2g F + 6.1g W | → 391.8g / 273.9g | hidden 45.7g F + 34.3g W | → 354.3g / 245.7g |
| One Step Down: 400g / 100% | hidden 7.1g F + 7.1g W | → 392.9g / 272.9g | hidden 40g F + 40g W | → 360g / 240g |
| One Step Up: 500g / 125% | hidden 6.3g F + 7.9g W | → 493.7g / 342.1g | hidden 44.4g F + 55.6g W | → 455.6g / 294.4g |
| Two Steps Down: 1000g / 50% | hidden 9.5g F + 4.8g W | → 990.5g / 695.2g | hidden 133.3g F + 66.7g W | → 866.7g / 633.3g |
| Two Steps Up: 400g / 100% | hidden 7.1g F + 7.1g W | → 392.9g / 272.9g | hidden 40g F + 40g W | → 360g / 240g |
Live Parameter Solver for How to Replace 3g (1 tsp) Fresh Cake Yeast
Dial in custom baker's percentages and export your adjusted 14.3g Starter formula for bake day.
Replacing Low-Inoculation 3g Fresh Cake Yeast in 400g Flour Without Shifting Hydration
Flour mass moves too, and bakers tend to forget it. The 7.1g of pre-fermented flour inside 14.3g of sourdough culture means the true total flour of your dough is not 400g but 407.1g once the starter is added, which is what makes 70% the correct target rather than the naive 70%.
A hybrid is often the best answer in practice: use 14.3 g of levain to preserve the flavour of the original 3 g dose, but plan the schedule as if you were using 80g at 20% inoculation, because the acid load and the fermentation time both follow the latter.
3-Step Conversion Checklist (3g Fresh Cake Yeast → Sourdough in 400g Flour)
- Autolyse First: Combine 360g flour with 240g water (holding back 10% for salt) and rest 45 minutes.
- Add 80g of Ripe Levain: Pinch in the culture, add 2% salt with the reserved water, and mix until the dough is cohesive.
- Four Folds: Space two stretch and folds and two coil folds 30 minutes apart to build gluten without tearing the gas cells.
- Bulk, Shape and Retard: Reach the target rise, shape, and refrigerate 12–16 hours at 38°F before the final bake.
Cereal Chemistry & Bench Execution FAQs
What salt level should I use on the converted 400g dough?
Keep 2% of the total system flour, which on a 400g base with 40g of starter flour is about 8.8g of salt.
How do I convert a sweet or enriched recipe with 3g of Fresh Cake Yeast?
The grain 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.
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).