The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Levain Calculation

DanAyo's picture
DanAyo

Levain Calculation

Certain repeated questions turn up from time to time that are valuable, but the replies required are lengthy. This post was written with the thought that it can be linked for future replies to the question of Levain and how it is calculated.

There are 2 main methods used to calculate the percentages of Levain used in a formula.

  1. Total levain weight divided by the flour weight of the final dough

  2. Levain flour divided by TOTAL flour used in the recipe 

The various methods of calculating Levain can be confusing. Realize that many highly respected bakers use either of these methods. 

Method #1 -  Total levain weight (including the water and flour) divided by the flour weight of the final dough

This is best explained as the Levain being considered an ingredient according to Bakers Percentages, the same way salt would be calculated in a formula. It is important to realize that the weights of both the water and flour in the Levain are not part of the Total Water and Toal Flour in the formula.

Example -
Flour = 1000g (100% Bakers Percentage)
Water = 700g (70%)
Salt = 20g (2%)
Levain = 240g (24%) - Since the hydration of the Levain is not specified we commonly assume 100% hydration
Total Dough Weight = 1960g
Hydration = (Total Water = 700+120=820 ) + (Total Flour = 1000+120=1120) 820/1120=73.2% Hydration

Method #2 -  Levain flour divided by TOTAL flour (including the flour in the Levain) used in the formula
This method is called the Percentage of Pre-Fermented Flour (PFF). It is this method that has been adopted as the standard by the Bread Bakers Guild of America (BBGA). Most bakers on The Fresh Loaf use this one.

Example -
Total Flour = 1000g (100%)
Total Water = 700g (70%)
Salt = 20g (2%)
PPF (Pre-Ferment) = 12% Levain Hydration = 100% - With this method the hydration of the Levain is always specified. In this example there is 120g water and 120g flour in the levain.
Total Dough Weight = 1720g
Hydration = (Total Water 700g) + (Total Flour 1000g) 700/1000= 70% Hydration
NOTE - the dough minus the Levain contains 580g Water and 880g Flour.

Since this post was published as a reference for future questions, please let me know if you find errors or have additional pertinent information.

 

floureverywhere's picture
floureverywhere

Thank you so much for this clear explanation.  One thing I am still confused about is what percentage of starter to add to the Levain.  In other words, when I started baking sourdough, I followed recipes that would call for making a levain the night before with 100g water, 100g flour and 1 tablespoon active starter.

I am now trying to move away from the "recipe" model and work off of baker's percentages... but most discussions about doing so do not include the amount of starter.  So in your Method 2 example above -- how much starter would you mix with the equal parts flour and water when making the levain the night before?

proth5's picture
proth5

And I really need to wrap up commenting because I'm displaying my signature crankiness...

Of course, the problem starts with a formula calling for 1 TBL of starter rather than a weight, but you could weigh it and find out what it weighs.Once you know that, you can do the calculations.

According to the BBGA standard, you should write your formula to include the percentage of seed (what you call starter) (or yeast) that you should include in the preferment. So, if you were doing a starter that contained 100 gms of flour, 100 gms of water and 5 gms of seed. The percentages would be :

Flour - 100%

Water - 100%

Seed - (5/100) - 5%

Now, what should that seed percentage be? That's the art. How long do you want it to take for the preferment to mature? At what temperature will the preferment ripen. What type of flour is it? That I cannot tell you. But if you start from the baseline formula - "I used 5% seed in my preferment and it became fully mature much earlier than I wanted it to - maybe next time I should use less" or conversely "I used 5% seed in my preferment and when I came down in the morning to do the mix, it wasn't mature - maybe next time I should use more." - you have a basis to observe and learn.

Hope this helps. Now I must quit this.

floureverywhere's picture
floureverywhere

You're a good person.  :-)

DanAyo's picture
DanAyo

The percentage of starter you use to ferment your levain depends upon how long you want to ferment to maturity and also the room temperature. Each starter can be different. Trial and error will quickly work things out.

example -

If I want to ferment the levain overnight and it is warm (77F) I’d mix 20% starter or 1 to 5. Let’s say the hydration for the levain is 100% and the formula calls for 300 grams.

  • add all ingredient percentages - 100% flour + 100% water + 20% starter = 220%
  • divide the weight needed by the total percentage - 300/220=1.36 (rounded off)
  • multiply 1.36 times 100% for the weight of the flour 100*1.36=136
  • multiply 1.36 times 100% for the weight of the water 100*1.36=136
  • multiply 1.36 times 20% for the weight of the starter 20*1.36=27

136+136+27=299 (the discrepancy of 1 is due to rounding numbers)

There are also other ways to calculate this. But I don’t want this to be more confusing.

Baker’s Percentages can appear difficult at first, but once learned it makes complete sense. It is a method that will greatly benefit most bakers. And most of us use spreadsheets to auto-calculate for us.

If you need more help, don’t hesitate to ask.
I hope this helps,
Danny

OH! If you wanted to ferment approximately 4 (depending on the strength of your starter) you could mix 1:1:1 (s:w:f) and keep the starter at 80-82F. In this case it would be 100g starter + 100g water + 100g flour

barryvabeach's picture
barryvabeach

Dan,  I don't if it would help ,  or make it more confusing,  but I would add the part in italics:

Total Flour = 1000g (100%)
Total Water = 700g (70%)
Salt = 20g (2%)
PPF (Pre-Ferment) = 12% Levain Hydration = 100% - With this method the hydration of the Levain is always specified. In this example there is 120g water and 120g flour in the levain.
Total Dough Weight = 1720g
Hydration = (Total Water 700g) + (Total Flour 1000g) 700/1000= 70% Hydration
NOTE - the dough minus the Levain contains 580g Water and 880g Flour.

While the calculations are based on total flour, the recipe would look like this:

Flour  880 grams

Water 580 grams

Starter 100% hydration 240 grams 

Salt 20 grams.