The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Baker's percentage. Long and ardous calculations.

ibor's picture

Baker's percentage. Long and ardous calculations.

I understand and use the baker's percentage formula for calculating the amount of bread one wants to make, based in the percentage of its components. Flour is 100%  and the rest of the ingredients vary accordingly.

How do you calculate the bread's final weight when you use a sponge like in Reinhart's New York Deli Rye - The Baker's Apprentice ? In other words, how did Mr. Reinhart arrive at the  formula he gives for the bread, based in the percentages he provides?

The "Baker's Math System" from his book does not present, in my opinion, a clear explanation.

To abbreviate, I will not include all my failed calculations or opinions, of which I have more than enough.



Makes 4 lb of bread

Rye Sponge Starter

7 oz sourdough starter
4.5 oz white rye flour
4 oz water
12 oz onions
1 oz vegetable oil

Final Dough

16 oz bread flour
4.5 oz white rye flour
1 oz brown sugar
.56 oz salt
.22 oz yeast
.22 oz  caraway seeds
1 oz vegetable oil
8 oz lukewarm buttermilk or milk
2 to 4 oz water, or as needed

egg white, for wash (optional)



Baker's percentage formula

New York Deli Rye       %

Rye Sponge Starter

Barm                             156

White Rye Flour           100

Water                              88.9

Onions                           267

Vegetable Oil                  22.2


Total                             634.1

Final Dough

Rye sponge starter          139

High-gluten flour              78

White rye flour                 22

Brown sugar                      4.9

Salt                                    2.7

Instante yeast                    1.1

Caraway seeds                  1.1

Shortening                        4.9

Buttermilk                       39

Water (aprox)                  14.6


Total                                307.3


Let the experts speak

embth's picture

but it looks like a good recipe.  I may have to try it for our New Year's Eve celebration.

oregoncrepe's picture

I'm at home and not at the bakery (where my well worn copy resides)  but I use his formulas for a number of breads. He does skip a step.    I converted his math to spreadsheets in order to make enough dough to fill orders for various sizes of rolls, e.g. 36 baguettes at 8 oz = 18 lbs of dough  (don't forget a few % for bowl waste, etc.).

But how much is each part?  Here's how to find out.

I found I needed to work backwards from desired weight to calculate the % contribution for each of the first two steps to the final.  Here is what I do, applied to the formula you posted.

The starter is 139% of final dough weight. The starter is two parts - the barm and the sponge.  

Using your figures,  the sponge part makes up about about 3/4 of the starter  634.1% - 156% = 478.%  which is 75.24% of the starter, the barm is 24.76% (not in bakers percent, just proportions of the starter)

We know the starter is 139% of the total.    We also know the starter is made up of two parts (156% + 478.1%).  Solving for the barm contribution to the total gives:

(156%/634.1%) * 139%  is the same as 24.76% * 139 =  34.1964 or 34.2% of the final

Therefore the bakers formulas percents of the final dough are: barm is 34.2%,  sponge is (139%-34.2%) or 104.8%

We can now rewrite that portion of the total dough formula above:

Final Dough

Rye sponge starter          139

Barm                                 34.2

Sponge                           104.8

High-gluten flour              78

White rye flour                 22


I hope that helps.  Happy New Year