50
g
50
g
400
g
287.5
g
75
%
50
g
50
g
400
g
287.5
g
75
%
The Sourdough Hydration Calculator is an advanced tool designed to help sourdough bakers calculate precise water and flour amounts for their final dough, accounting for the flour and water already contributed by the levain. This is the key difference between sourdough hydration calculations and standard bread hydration: your sourdough starter or levain contributes both flour and water to the overall formula, and failing to account for these contributions leads to a final dough with different hydration than intended.
Many beginning sourdough bakers follow recipes that already account for levain contributions. But when you want to develop your own formulas, adjust hydration from one recipe to another, or scale a recipe accurately, you need to understand the 'overall formula' — the complete picture of all flour and water in your dough, including what comes from the levain.
Sourdough baking at higher hydrations (72-85%) is favored by artisan bakers for the open, irregular crumb structure it produces in well-fermented doughs. The complex fermentation of wild yeast and lactic acid bacteria strengthens gluten through organic acid production, allowing the dough to handle hydration levels that commercial yeast doughs cannot. However, this means sourdough hydration management is more nuanced than standard yeasted bread.
This calculator helps you work backwards from your desired overall hydration to determine how much additional flour and water to add in the final mix, given the flour and water already contributed by your levain. This allows you to maintain precise hydration across different levain sizes and hydrations without losing track of the math.
Whether you're baking a classic Tartine-style country loaf, experimenting with high-hydration porridge breads, or trying to replicate the exact hydration of a recipe you tasted, this tool makes the calculation clear, fast, and accurate.
The calculator first breaks down the levain into its constituent flour and water:
Flour in Levain = Levain Weight / (1 + Levain Hydration / 100)
Water in Levain = Levain Weight - Flour in Levain
Then it calculates the additional flour and water needed to reach the target overall hydration:
Additional Flour = Total Flour - Flour in Levain
Total Water Needed = Total Flour × (Target Hydration / 100)
Additional Water = Total Water Needed - Water in Levain
Sourdough hydration guide: 70-72% produces a moderately open crumb suitable for beginners, easier to shape without bench scraper skills. 73-78% is the sweet spot for most artisan sourdough bakers — open crumb, manageable handling, beautiful ear when scored. 78-85% produces very open, irregular crumb like Tartine or Chad Robertson style, requires confident shaping skills and usually cold retard. Above 85% is very advanced; dough is pourable, baked in pullman pans or using coil fold technique only.
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The 100g of 100% hydration levain contributes 50g flour and 50g water. Add 400g more flour and 287.5g more water at mixing. The overall formula confirms 75% hydration across the entire dough.
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An 82% hydration sourdough for an open, lacy crumb. The levain's water contribution is subtracted from the total water needed, giving precise mixing quantities. Handle with wet hands and use the stretch-and-fold method.
When you add levain to your dough, you are adding both flour and water simultaneously. If you ignore this and add your full water quantity to the dough without accounting for the water already in the levain, your dough will be wetter than intended. This calculator ensures your actual hydration matches your target.
Overall formula hydration includes all water and flour from every source — autolyse water, levain water, and mixing water all combined, divided by all flour from levain and final mix. This is the true hydration of your finished bread and is what you should use when comparing recipes or adjusting a formula.
Levain percentage (levain weight as a % of total flour) affects fermentation speed and flavor. A 15-20% levain produces a well-balanced sourdough flavor with moderate acidity. A 25-30% levain ferments faster with slightly less complexity. Very low levain percentages (5-10%) with long cold fermentation produce more complex, tangy flavors.
Yes. If you autolyse your flour before adding the levain and remaining water, the autolyse water is still part of your overall hydration. This calculator adds all water together in the overall hydration figure. Many bakers hold back 10-20g of water during autolyse and add it with the levain to help with incorporation.
If your levain is not ready (not peaked, not airy), do not mix your dough. A failed levain in the dough will not leaven the bread properly. Rebuild your levain from fresh starter, or give your existing levain more time. You can slow down flour fermentation by refrigerating your mixed flour and water until the levain is ready.
Bassinage is the technique of holding back 5-10% of the total water and adding it gradually during mixing after the dough has come together. This helps control dough consistency and is especially useful at high hydrations. The held-back water is still part of your overall hydration calculation.
At high altitude, lower atmospheric pressure causes dough to rise faster and air bubbles to expand more rapidly. You may need to reduce hydration slightly and ferment at cooler temperatures to maintain control. Some bakers also reduce the amount of levain at altitude to compensate for faster fermentation.
Whole grain flours absorb more water than white flour, so the same hydration percentage will feel drier with whole grains. When substituting 20-30% whole wheat or rye into a formula, increase hydration by 2-5% to maintain similar dough consistency. More whole grain requires proportionally more water.
Always weigh water by grams, not volume measurements. 1 gram of water = 1 milliliter, making grams and milliliters interchangeable for water, but weight scales are more accurate than measuring cups, especially for small adjustments. Water temperature is also important — use water at 75-80°F for standard fermentation timing.
Higher hydration doughs are more fluid and harder to score cleanly. The blade drags through the wet dough surface rather than cutting crisply. For better scoring at high hydration, cold proof the shaped loaf overnight (36-40°F), score while cold, and load directly into a preheated Dutch oven. The cold temperature firms the dough briefly for a cleaner cut.
Roboculator Team
The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
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