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Bakers math and lesson 3

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ex99125b's picture

Bakers math and lesson 3

The web is replete with examples of how to do bakers math and I think that I have a good handle on it, enough to put together a spreadsheet anyways. However, I seem to trip myself up on preferments. Could  someone show me the bakers percentages for the recipe in lesson three? Enough of them so that I could start with the desired dough weight and work my way back through the recipe? I certainly would appreciate it.

LindyD's picture

Susan of Wild Yeast did a lovely tutorial on baker's percentages in 2008.  Here's the link to the fourth part of her tutorial, which deals with preferments.

Hope you find it helpful.

ex99125b's picture

thank you. Her site is well done and it helped me out when I first explored BP stuff. I'm just missing something and was hoping someone could do the percentages and I could figure the system out by looking at results. Perhaps just looking at it agian will do.

proth5's picture

in these discussions of Bakers Math with preferments is the percentage of the total flour pre fermented.  In the example referenced above, the simple piece of information that 34% of the total flour (that is the flour in the oveall formula) is prefermented has been omitted.  Without that vital piece of information - we cannot understand the amounts in the pre ferment formula - or really - the nature of the bread.

So if our overall formula's total flour is 1368 gms - we know that 34% of it is prefermented which allows us the basis to calculate the 468 gms of flour in the pre ferment formula.  There seems to be no explanation as to why the gram amount of flour that has been chosen has been chosen in the writeup referenced above.

The precentage of flour pre fermented is the glue that holds the system together and is equally applicable with one to a large number of pre ferments.

The Bread Baker's Guild of America (BBGA at has a standard for presenting formulas that also omits the calculation of baker's percentages on the final dough as they can be confusing and are not essential to understanding the dough itself. 

I do a lot of formula development and the more I do, the more I appreciate the BBGA standard as it is simple to use and allows rapid development of variants on a given formula. Many people object to somehow being "standardized", but I consider that there are many instances in our life (the number of holes in shower curtains - the side of the car where the steering wheel goes, etc) where we accept standards as a way to ease our life without destroying one whit of creativity.

Hope this helps.

ex99125b's picture

I am not sure that we are talking about the same thing... in lesson three, there are 140g (1 c) of flour in the sponge, about 280g (2 c) in the dough, for a total of 420g. There are 117.5 g of water in the sponge and 235 g of water in the dough. for a total of 352.5 g. A list of BP for this recipe has me stumped.

proth5's picture

I don't really know to which "Lesson 3" you are referring.  I was referring to the Baker's Percentages with Pre ferments link posted by LindyD.

Either way, once again we get ourselves in trouble not knowing the percentage of flour prefermented.  So I'll do this the right way

Overall Formula

                                   Percentage             Wt(gms)

Total Flour                     100%                       420

   Water                            84%                        352.5


This is what is written first.  It allows us to understand the characteristics of the dough that we will obtain when it is completely mixed.

The next piece of data is what ties everything together:

Percentage of flour in preferment  33%  (140/420 - it is backwards to need to calculate this. When designing a formula one would normally decide that x percentage of the flour is to be pre fermented as the percentage of flour pre fermented will impact the properties of the dough and bread when mixed or baked.)

It would also be best if we then determined the desired hydration of the prefement which in this case is 84% ( 117.5/140 same as the dough, but this is not required to be so - it could be higher or lower.  Again, this is thinking backwards. Normally one determines what the hydration of the pre ferment should be and then figures the water weight from there.  This tells us the characteristics of the pre ferment)

Now we write the columns for the pre ferment by first calculating the weight of the flour in the pre ferment which is 420*.33 or about 140gm.  This is then assigned a percentage of 100%

                                 Percent                                                                              wt(gms)

Flour                          100% (if only one flour is used always 100%)             140 (calculate this first - total flour times percentage of flour pre fermented)

Water                           84% (baker decides on this number)                           117.5 (or  140 *.84 - baker calculates this number)

When these two are done we calculate the numbers for the final dough

                                   Wt (gms)

Flour                            280 ( which is 420 - 140  Overall minus pre ferment)

Water                           235 (which is 352.5 - 117.5   Overall minus pre ferment)

Pre ferment                 257.5


There is no need for calculating the final dough percentages as these tell us little or nothing.

Various totals can also be calculated (such as the total of all percentages in the overal formula or the preferment and this is quite useful), but these are the basic steps expressed correctly and in the correct order for creating and expressing a formula with a pre ferment in Baker's Percentages.

Sorry if I sound weary.  The BBGA has an excellent explanation on these and I have seen so many people do beautiful  write ups that essentially confuse a very simple technique that I really should have just stepped away from this.  But having stepped in, I have presented the correct way to think about and compute these numbers.

Hope this helps.

ex99125b's picture

thank you very much for taking your time and allowing me this understanding. The gift of your time is as a gift of a loaf of bread, and I accept it as such. Thank you.

JOHN01473's picture


i developed this from Hamelman's book "Bread: A Baker's Book of Techniques and Recipes".

if it helps i could email it to you.