Convert 6g (2 tsp) Fresh Cake Yeast to Sourdough Starter (500g Flour Recipe)
Zero-drift flour and liquid deduction math for converting 6g of fresh cake yeast into 50%–125% hydration sourdough levain on a 500g base.
Swapping 6g (2 tsp) Fresh Cake Yeast into sourdough on a 500g flour + 350g liquid formula yields 100g active levain at 20% baker's math (subtracting 50g flour and 50g water for 450g F / 300g W), or 28.6g by direct packet scaling (-14.3g F / -14.3g W).
- Direct Yeast Equivalent
- 28.6g StarterDeduct 14.3g flour & 14.3g 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 (6g Fresh Cake Yeast → 500g dough)
Starter hydration shifts the deduction asymmetrically: a stiffer levain carries more flour and less water per gram.
| Hydration of Levain | Yeast-Equivalent Starter | Remaining Main Formula | Baker's-Math Starter | Remaining Main Formula |
|---|---|---|---|---|
| Case 500g @ 75% [Baseline] | 28.6g levain | subtract 16.3g flour, 12.2g water | 100g levain | subtract 57.1g flour, 42.9g water |
| Case 400g @ 100% Stiffer Starter | 28.6g levain | subtract 14.3g flour, 14.3g water | 80g levain | subtract 40g flour, 40g water |
| Case 500g @ 125% Wetter Starter | 28.6g levain | subtract 12.7g flour, 15.9g water | 100g levain | subtract 44.4g flour, 55.6g water |
| Case 1000g @ 50% Lighter Starter | 28.6g levain | subtract 19g flour, 9.5g water | 200g levain | subtract 133.3g flour, 66.7g water |
| Case 500g @ 100% Heavier Starter | 28.6g levain | subtract 14.3g flour, 14.3g water | 100g levain | subtract 50g flour, 50g water |
Custom Batch Recalculation Engine
Fine-tune starter hydration between 50% stiff and 125% liquid while keeping your yeast ↔ sourdough conversion ratios locked.
Why 6g Fresh Cake Yeast Cannot Be Swapped in 500g Flour Without Deducting Starter Water
The fresh cake yeast you are replacing is a single strain with a predictable gas curve, and the sourdough culture 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.
A hybrid is often the best answer in practice: use 28.6g of levain to preserve the flavour of the original 6g dose, but plan the schedule as if you were using 100g at 20% inoculation, because the acid load and the fermentation time both follow the latter.
3-Step Conversion Checklist (6g Fresh Cake Yeast → Sourdough in 500g Flour)
- Scale the Recipe Sheet: Rewrite the original 500g, 350g, 6g fresh cake yeast formula as 450g flour, 300g liquid, 100g levain and 2% salt.
- Hydrate the Flour: Mix the adjusted flour and 90% of the liquid and rest 45 minutes to fully hydrate the starch.
- Add Levain, Salt and the Last 10%: Work in 100g of culture, 2% salt and the reserved water, then complete the gluten with 3 coil folds.
- Ferment, Shape, Retard: Let the 500g dough reach +50% volume, shape tightly, cold-proof 12–16 hours and bake at 450°F for a blistered crust.
Technical Q&A: Convert 6g (2 tsp) Fresh Cake Yeast to Sourdough
Does the type of commercial yeast change the starter weight?
Yes. Fresh Cake Yeast has its own potency per gram, so 6g of it converts to 28.6g of sourdough culture rather than the 100g that the 20% rule would prescribe on a 500g base.
Does converting to sourdough change the dough weight?
Yes, slightly. The 500g flour and 350g liquid original carried 6g of dry yeast; the levain version carries 28.6g of starter instead, so expect a small shift in finished loaf weight.
Can I halve the recipe and still use 6 grams of Fresh Cake Yeast?
You can, but the effective inoculation doubles, so 28.6 grams of levain on half the flour ferments faster than the original. Plan for a shorter bulk.