How to use the preferment split calculator
- Enter the total flour in the recipe, the overall hydration and the salt percent. The salt percent is an example you can change.
- Enter the percent of the flour that goes into the preferment and its hydration. A poolish is often 100%, and a biga is often about 50%.
- Read the weights for the preferment first, then the flour, water and salt to add to the final dough.
- Use the two-stage table to check that flour and water add up to the total.
Formula
preferment flour = total flour x preferment share
preferment water = preferment flour x preferment hydration
final dough flour = total flour - preferment flour
final dough water = total flour x overall hydration - preferment water
The preferment flour and water are part of the recipe totals, not extra. Baker's percentages use total flour as 100%.
A 1,000 g recipe with a poolish
The recipe has 1,000 g of flour, 70% overall hydration (700 g of water in all) and 2% salt (20 g). A poolish takes 30% of the flour, 300 g, and equal weight in water at 100% hydration, 300 g.
The final dough then needs 700 g of flour, 400 g of water and 20 g of salt. Flour recombines to 1,000 g, water to 700 g and the whole dough weighs 1,720 g before yeast. A biga at 40% of 800 g of flour and 50% hydration gives 320 g of flour and 160 g of water, with 480 g of flour and 360 g of water for the final dough.
Why split a formula
A preferment is a small early mix that ferments before the final dough. Many recipes list only the finished total, so a baker has to work out how much flour and water go into the preferment and how much is left. The split keeps the overall hydration the same, which keeps the dough consistent from batch to batch.
Checking a split
If the preferment holds more water than the whole recipe allows, the final dough would need a negative amount, and the page reports that instead of showing a number. To scale a recipe, use the Baker's Percentage Calculator. To check hydration of a starter, use the Sourdough Hydration Calculator, and to plan water temperature use the Desired Dough Temperature Calculator.
Assumptions and limits
- The preferment is made of flour and water only, with its yeast or starter not counted.
- Hydration is water weight as a percent of flour weight.
- Salt is added to the final dough and is a percent of the total flour.
- Weights are shown to 0.1 g.
Frequently asked questions
How much flour should go in a preferment?
It depends on the recipe and the style of bread. The share in the box is an example, so use the share your own formula calls for.
Does the preferment count toward total hydration?
Yes. The overall hydration includes the water in the preferment, which is why the water for the final dough is the total water minus the preferment water.
Why did I get an error about water?
The preferment would hold more water than the recipe contains at the overall hydration you chose. Lower the preferment share or its hydration, or raise the overall hydration.
Where does the yeast go?
This page splits flour, water and salt only. Add the yeast or starter amounts that your method uses to the preferment and the final dough as the recipe directs.