How to calculate levain percentage

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jason.e.bakes on 13 Jun 2020 at 17:51

Hello all,

I've been diving deeper into baker's math and sourdough bread, and I have a question about how to calculate levain percentage. I've been reading Flour, Water, Salt, and Yeast by Ken Forkish as well as The Bread Baker's Apprentice by Peter Reinhart, and I've noticed that there are different ways to calculate baker's percentages. These different methods, as I understand them, then lead to different ways to calculate the levain percentage. So, I wanted to check in with other breadheads more experienced than I - how do you calculate your levain percentage?

 

1)     Total levain weight divided by the flour weight of the final dough mix/autolyse;

 

2)     Total levain weight divided by the TOTAL flour used in the recipe, including the flour in the levain itself, or

 

3)     Levain flour divided by TOTAL flour used in the recipe.

 

For example, if the recipe is as follows:

80% bread flour

20% whole wheat

78% hydration

2% salt

20% levain

 

then the levain could be different amounts according to which method is used. Is the levain 20% of (bread flour + the whole wheat flour) or is the levain 20% of (bread flour + whole wheat flour + the flour used in the levain itself). I see bakers include their levain percentage all the time, but I’m just not sure which method they’re using to calculate it. My gut tells me that they are treating the levain percentage as the total levain weight divided by the flour used in the final dough mix/autolyse, but I wanted to check with others to be sure. Any insight would be greatly appreciated!

Bakers math is a percentage of total flour weight. In your example it would be 20% of the combined white and ww flour. If you want to calculate hydration (which I think is the cause for confusion) then you would consider the flour/water in the starter.

This what I learned from Hamelman. I explain it using an example:

Overall formula for a 750g sourdough 

Bread flour 100% - 449 g

Water 65% - 292 g

Salt 1.9% - 9 g

He also gives the % of flour to pre-ferment. I will preferment 15% for this example with 100% hydration. I make sure the starter is the same hydration as the levain build.

So, the levain will include:

Bread flour - 67 g (15% of the 449 g)

Water - 67 g

Starter 20% of 67g = 13 g

Total levain = 448 g

When the levain is ripe, you remove the amount of starter used to seed it.  I am then left with 135 g for the final mix. 13 g is left over to feed the starter for next time.  In this way you have successfully pre-fermented 15% of the flour.

Why 20% of the starter as a seed for the levain? That is totally dependant on how long before you want to do the final mix, and what temperature you mature the levain in.  20% is good for a 12-hour levain at 21C. You make adjustments depending on your environment and how soon you want it ready.

So for the final mix, you subtract the amount of flour and water you used in the levain from the overall formula, and add 135 g of levain. Total is 750 g.

BF 382 g

water 225 g

salt 9 g

levain 135 g

Total 750 g

 

In my opinion it is very simpel and we must be aware not to over complicate matters. 

If your levain is 80 gram flour, 80 gram water, 40 gram starter. 
You got 200 gram levain.

 

When you bake using 1000 gram flour 200 gram levain is 20%

Now see, I would look at the posted recipe with 20% whole wheat and 20% levain and say to myself.  "Ok, you WW, you go diving into the levain and get all softened up and wrinkled overnight (22°C) while feeding my yeastie beasties."  Then I only have water to calculate!    :) 

  • Just pour all the water for the recipe into a pitcher and take what I need for the levain, then cover.   But most of the time laziness demands I pour the leftover warmish water from my water cooker and do the following:
  • Or tare the flour in the bowl on the scale to "0" and add the same weight as the WW.  Then subtract that water weight from the total water to get the dough water.

I look at the flour weight for the starter to determine the amount of culture inoculate.  If the starter has say 100g of flour, I give it a decent blob or heaping tablespoon of starter or roughly the same as my feeding ratio. Sometimes more if the kitchen is cool or of I want a milder tasting crumb. I know when my starter will be peaking and ready with different temps., flour and water amounts.   Remove the inoculate amount before using.  Amazing what influence an extra tbs of starter culture can do! 

I think there is the lowest possibility of confusion if we talk about percentage of prefermented flour.  Take the total flour in the levain and divide it by the total flour (including the levain flour) in the dough, that would be the percentage of prefermented flour.

Methods 1 and 3 are both perfectly valid. 2 is madness!

The example you gave depends upon how you interpret it... From the responses given here, some are seeing it as the total formula while others are seeing it as the final dough formula. I'm in later camp because it lists % "levain", which therefore leads me to believe it is being treated as an ingredient. If it were the total formula then it should state % "pre-fermented flour" and be separated to make that distinction since it would be in this case a stat.

In both cases there would be need to be more information regarding how the leavin is made to fully grasp the formula. Your example doesn't tell the baker what hydration the levain is.

This post was very helpful and cleared up a lot of my confusion - thank you for making it!

Sometimes I am not sure what calculation for the Levain the author is using. But if you take the Total Dough Weight (TDW) you can work down from there and figure things out.

If the author uses Pre-Fermented Flour or PFF you know his calculation.