## 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.

Ingredients

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**

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

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

backwardsfrom desired weight to calculate the % contribution foreachof the first two steps to thefinal.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

finalTherefore the bakers formulas percents of the

final doughare: 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

Richard