Change Sourdough from 80% to 70% Hydration Without Changing Loaf Size
A worked 910 g recipe: count the flour and water in starter, lower hydration, and keep total dough weight constant with the recipe converter.
Start with the whole recipe
Our example has 450 g flour, 350 g water, 100 g starter at 100% hydration, and 10 g salt. The starter contributes another 50 g flour and 50 g water. Total flour is 500 g; total water is 400 g. That is 80% hydration and 910 g dough.
Dividing only the added water by the added flour gives 77.8%. That leaves out the starter and describes a different ratio. Enter the weights that actually go into the bowl and the hydration of the starter you use.
Why reducing water alone changes the loaf size
Keeping total flour at 500 g, a 70% target needs 350 g total water. Subtract the starter’s 50 g water: add 300 g water instead of 350 g. This makes 860 g dough, not 910 g. Use the “Total flour” option when that smaller yield is acceptable.
To keep 910 g dough instead, choose “Dough weight”, set the target to 910 g and hydration to 70%. The converter preserves the starter, salt and other dry additions as proportions of total flour. It increases the flour base to make up for the lower water ratio.
Check the revised ingredient weights
The salt is 10 ÷ 500 = 2% of total flour. With no other additions, target flour = 910 ÷ (1 + 0.70 + 0.02) = 529.07 g. Keep the starter at 100 ÷ 500 = 20% of total flour: use 105.81 g starter. Half is flour and half is water.
The resulting additions are 476.16 g flour, 317.44 g water, 105.81 g starter and 10.58 g salt. Including the starter gives 529.07 g flour and 370.35 g water: 70% hydration. The table rounds each ingredient to 0.1 g; the calculation uses unrounded values.
| Ingredient | Original | Revised |
|---|---|---|
| Flour added to dough | 450.0 g | 476.2 g |
| Water added to dough | 350.0 g | 317.4 g |
| Starter added to dough | 100.0 g | 105.8 g |
| Salt | 10.0 g | 10.6 g |
| Total dough | 910.0 g | 910.0 g |
Use the conversion for your own recipe
Open the example below, replace the original ingredients, and choose which quantity to keep constant. For two equal loaves from this example, change target dough weight to 1,820 g. Each revised ingredient doubles. A recipe with no starter works too: enter zero for starter.
Combine flour blends into the flour field. Group oil, sugar and dry additions in “Other ingredients”, then scale each individual addition by the displayed factor. Milk and eggs contain water, so entering their full weight as “Other” will not give their true contribution to hydration. Calculate that separately.
Copy the comparison, share its numeric input link, or save a named recipe in this browser. The new starter amount links directly to the levain builder. Neither a hydration percentage nor equal dough weight predicts identical handling, fermentation or baked loaf volume. This is a formula conversion, not a tested baking result.