Tip - Different Levain Calculation %

Unfortunately, the percentage of Levain is calculated differently by different bakers.

There are two basic methods to describe the Levain.

1. Percentage of the Total Flour weight (Levain is listed as an ingredient)
2. Percentage of Pre-Fermented Flour (PPF)

1. Percentage of Total Flour Weight (Levain is listed as an ingredient)
Let’s assume the Total Flour Weight is 1000g and the Percentage of Levain is 20%. In this scenario the hydration of the Levain should be given. Let’s assume it is 100%. 1000x.20=200. Since the Levain is 100% hydrated it contains 100g water and 100g flour. You can see by this example that without knowing the hydration of the levain, accurate calculations are not possible. Using this method the Total Flour Weight is 1100g.

2. Percentage of Pre-fermented Flour (PPF)
This indicates the amount of flour that is taken from the Total Flour Weight to build the Levain. If the Total Flour in the formula is 1000g and the PPF is 20%, then 1000x.20=200. The hydration of the Levain doesn’t affect this calculation. So 200g flour is used in the Levain, leaving 800g flour for the final dough. This method maintains an accurate accounting of the hydration of the final dough. Regardless of the hydration of the Levain. Studying the image of the spreadsheet below may clarify things, if needed.

In my opinion the Percentage of Pre-fermented Flour is best. But some expert bakers use method #1.

How does listing the Levain as the Percentage of Total Flour Weight affect the actual hydration percentage?
Total Flour Weight = 100%
Water Weight = 70%
Levain = 30%

Let’s assume the Formula calls for 1000g flour. Remember - the weight of the water and flour in the Levain are not considered when it is listed as an ingredient. In the case 30% of the Total Flour listed in the formula will be the weight of the Levain. The dough hydration is shown as 70%, which would be 700g water.
Let’s suppose the Levain hydration is 100%.
Levain weight is 300g (1000x.30). So, 150g water + 150g flour.
Actual hydration is 700+150=850 water + 1000+150=1150 flour. To calculate the actual hydration the water and flour contained in the Levain must be considered.
850/1150=73.9. The true hydration is ~74%. Remember the dough is shown to have a hydration of 70%.

Study the spreadsheet below paying special attention the the water and flour.
NOTE - Let’s suppose the Levain hydration is 80% instead of 100.
.80x175=140g water instead of 175. The final dough will now use 395g (535-140=395) water instead of 360.
The true hydration remains the same no matter what the dough hydration might be.
Altering the hydration of the Levain will cause the water in the Final Dough to change.

How does listing the Levain as the Percentage of Pre-Fermented Flour (PPF) affect the actual hydration percentage?

Total Flour Weight = 100%
Water Weight = 70%
PPF = 30%

Assume the Total Flour Weight is 1000g. The PPF is 300g (1000x.30=300). Let’s assume the hydration for the levain is 100%. BTW, using this method the hydration of the Levain is always indicated.
Since the Levain is 100% hydrated we know the flour weight is 300 and the water weight is also 300g. The total weight of the Levain is 600g.

The Final Mix will include all of the Levain (600g) + 400g water + 700g flour.