Convert any bread recipe from yeast to sourdough or sourdough to yeast. The calculator adjusts flour, water and fermentation time - so your hydration stays the same.
Yeast vs Sourdough Converter - Swap Your Bread Recipe
Convert any bread recipe from yeast to sourdough or sourdough to yeast. The calculator adjusts flour, water and fermentation time - so your hydration stays the same.
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Two directions, one conversion - swap your recipe's leavening agent without breaking the hydration
Sourdough starter is not just a leavening agent. It contains flour and water that change the total hydration of your dough. Replacing yeast with sourdough (or the other way around) without correcting those hidden ingredients results in dough that is too wet or too dry. This calculator handles both conversions and keeps the ratios intact.
How to convert a recipe - step by step
- Choose direction - select whether you are converting from yeast to sourdough or from sourdough to yeast.
- Enter flour mass - the total flour in your original recipe (not counting flour inside the starter).
- Enter leavening agent - yeast mass (if converting to sourdough) or starter mass and hydration (if converting to yeast).
- Select flavor intensity - mild (15-20%), medium (20-30%) or intense (30-40%) starter relative to flour. Only applies to yeast-to-sourdough conversion.
- Read results - the calculator shows the converted recipe with adjusted flour, water, new leavening agent amount and estimated fermentation time.
Conversion reference table
Quick reference for common recipe sizes. All starter amounts assume 100% hydration (equal parts flour and water).
| Original recipe | Replacement | Time change | Notes |
|---|---|---|---|
| 500 g flour + 10 g fresh yeast | 125 g starter | 1-2 h to 5-9 h | Medium flavor, -63 g flour, -63 g water |
| 500 g flour + 10 g fresh yeast | 175 g starter | 1-2 h to 3-6 h | Intense flavor, -88 g flour, -88 g water |
| 500 g flour + 150 g starter | 11 g fresh yeast | 5-12 h to 1-2 h | +75 g flour, +75 g water added back |
| 1,000 g flour + 300 g starter | 23 g fresh yeast | 5-12 h to 1-2 h | +150 g flour, +150 g water added back |
Common mistakes when swapping leavening agents
| Mistake | What goes wrong | Fix |
|---|---|---|
| Adding starter without reducing flour/water | Dough is too wet or too dry | Subtract the flour and water contained in the starter from the recipe |
| Keeping the same rise time after switching | Underproofed (sourdough) or overproofed (yeast) | Sourdough needs 3-14 h, yeast needs 1-2 h |
| Using a cold or unfed starter | Very slow or no rise at all | Feed the starter 8-12 h before use, at room temperature |
| Expecting the same taste after conversion | Disappointment - the flavor profile changes | Accept the difference: sourdough adds tang, yeast gives a neutral flavor |
Practical examples
Original: 500 g flour, 20 g fresh yeast, 325 g water, 10 g salt.
Converted (medium): 438 g flour, 263 g water, 125 g starter, 10 g salt. Zero yeast.
Fermentation changes from 1-2 h to 5-9 h. Richer flavor, darker crust.
Original: 500 g flour, 200 g starter (100% hydration), 300 g water, 10 g salt.
Converted: 600 g flour, 400 g water, 12 g fresh yeast, 10 g salt. Zero starter.
Fermentation changes from 5-12 h to 1-2 h. No tang, shorter shelf life.
Original: 1,000 g flour, 5 g instant yeast, 650 g water, 20 g salt.
Converted (mild): 913 g flour, 563 g water, 175 g starter, 20 g salt.
Fermentation changes from 1-2 h to 8-14 h. Subtle tang, better structure.
Original: 400 g flour, 120 g starter (100% hydr.), 100 g water, 100 g butter, 80 g sugar, 3 eggs.
Converted: 460 g flour, 160 g water, 9.2 g fresh yeast, rest unchanged.
Fermentation changes from 6-10 h to 1.5-2.5 h (butter and sugar slow it down).
Original: 800 g rye flour, 400 g rye starter (100% hydr.), 350 g water, 16 g salt.
Converted: 1,000 g flour, 550 g water, 20 g fresh yeast, 16 g salt.
Note: Rye bread without sourdough loses most of its characteristic flavor. Consider adding 1-2 tablespoons of lemon juice for a hint of acidity.
FAQ - Frequently asked questions
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