August 28, 2012

Baker's math

To paraphrase a famous political commentator: "I got into baking bread because I was told there would be no math. Boy, was I misled."

I'm joking, of course. I happen to think math is beautiful and that using math in baking enables us to achieve high quality, consistent results time and again. One of the best tools we have for writing and/or communicating recipes and formulas is what is generally known as "baker's math" or "baker's percentages."

Before I start glossing about baker's math, here's Rule no.1: Baker's math only works when measuring ingredients "by weight," rather than "by volume." Serious bakers generally prefer measuring by weight, because this method is a lot more accurate than measuring by volume. After all, everybody has a different way of measuring a cup of flour. Not to mention that not all cups are created equal.

So, there's an extra incentive for measuring by weight: you get to use baker's math! And by using it, you can better communicate with other fellow bakers half a world away. A 68% hydration baguette should be the same no matter where one happens to be in the world.

Baker's math expresses each ingredient in a formula as a percentage of that ingredient's mass to the total flour mass. Which means, the total amount of flour in the formula will be expressed as 100%, while all the other ingredients will represent fractions (or percentages) of the total amount of flour. A simple example should make it even easier to understand. Here's a very basic baguette formula: 1000 g all-purpose flour, 680 g water, 5 g instant yeast, 20 g salt. Using baker's math, this formula would look something like:

Basic Baguette Dough

1000 g all-purpose flour (100%)
680 g water (68%)
5 g instant yeast (0.5%)
20 g salt (2%)

Please note that with a formula written in this way, one can easily scale a batch up or down to suit one's needs. One can start by deciding what amount of dough/number of loaves one wants to produce, and easily figure out the amounts of all the ingredients necessary; or one can do the opposite, determine how much flour one has available and from there figure out the amounts for all other ingredients and how much dough will result in the end. The possibilities and variations are endless, and quite fun to play with. In other words, here we have a method of writing our bread formulas that is simple, intuitive, and elegant.

Or is it?

It can all get a little bit more complicated and even confusing at times when the formulas are more complex, particularly when we start using pre-ferments, soakers, and mashes. In fact, I have seen the same formula written in three different ways; all of them correct!

Let's take the above formula as an example and assume we are planning to produce it by pre-fermenting and soaking part of our flour. Let's say we'll do a 6-hour sponge, a 12-hour poolish, and a 12- to 24-hour soaker as part of our final dough. We might have something that looks like this:

Sponge (6 hours at room temperature):

150 g all-purpose flour (100%)
93 g water (62%)
1 g instant yeast (0.66%)

Poolish (12 hours at room temperature):

200 g all-purpose flour (100%)
200 g water (100%)
1 g instant yeast (0.5%)

Soaker (12–24 hours at room temperature):

150 g all-purpose flour (100%)
105 g water (70%)

As we assemble everything into our final dough, the formula will look like this:

Final Dough:

500 g all-purpose flour (100%)
282 g water (56.4%)
3 g instant yeast (0.6%)
20 g salt (4%)
244 g sponge (48.8%)
401 g poolish (80%)
255 g soaker (51%)

All of a sudden, this type of formula isn't that straight forward and easy to read, nor is it as simple as before to scale your batches up or down. No matter; this is still a valid way to communicate formulas and a very useful tool indeed for any baker.

And what is the point of all this little exercise, you might wonder.

The point of it is that in the past we've had "consistency issues" in the way we've written our recipes, not just on this blog, but also when developing new formulas for ourselves, or for our workshops. So this was something that was nagging us and didn't let us sleep at night. I'm not sure if this whole rant is completely intelligible, but if you have questions, don't hesitate to give us a shout.

And to end this: I've always found it very useful to have a recipe expressed both in "Total Formula" form, as well as in "Final Dough" form. Something similar to the example bellow:


  1. Do you add Sponge,Poolish and Soaker or just one of those three ?

  2. Just reread and found answer all three. Thanks