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The Baker's %: A blog post about how to do the maths

One of the first steps to making really good bread is understanding one very simple premise: that cakes are chemistry and bread is biology. I was working as a baker when one of my colleagues imparted this bit of wisdom on me and an enormous lightbulb lit up, illuminating what dough really was — every cake has a separate recipe with different ingredients. These respond to each other differently, producing a different cake each time. Bread however, is the opposite. All bread making is, is one almighty biology experiment, one where water, flour, yeast and salt discover how to live together, merrily, in a mixing bowl. But the ratios of these four pillars of bread making need to be kept, if not the same, then pretty similar, in the same way that we might keep a biology experiment under control.  We control this experiment by using something known as The Baker’s Percent. 


What is the Baker's %?

The Baker’s percent is a way of keeping the main ingredients of bread at the correct ratios. Bakers very often have to scale the amounts of dough they make daily up and down, as demand changes throughout the week, so this simple ratio of each ingredient makes sure that everything stays nice and even. 


The Maths

The baker’s percent is a funny thing — it does not refer to the total sum of all the ingredients, instead it revolves around the amount and type of flour that we are using for each recipe. Flour is the backbone of bread making. Every flour has a different property and needs to be handled differently. For this reason, we always start with flour.  We say that flour always equals 100% of any bread making recipe. 


As an example, let’s say that 100% of flour equals 1000 g of strong white Canadian bread flour. 

Bare this in mind as we go through the next steps of the Baker’s Percent. 


The next part of our Baker’s percent is hydration. I have called it hydration, not water, because sometimes we don’t use water in bread - we might use oil or milk or yoghurt etc... Depending on the flour and how ‘thirsty’ it is (wholemeal is very thirsty, rye is not so thirsty, for example), we can say that the hydration can range between 60% to even as much as 100%. 


60 - 100% hydration, if we are using the example of 1000 g of flour would be 600 g - 1000 g. If we are using Canadian bread flour, we know that we might need roughly 72% of water, so our recipe could be 720 g water. 


I must admit I have never baked with 100% hydration, but I do know it exists - the wetter your dough, the harder it is to manipulate, and many bakers equate a wet dough to skill! You might hear some bakers showing off about making bread with a 90% plus hydration level. 


Next comes salt.

The ratio for salt in bread has changed recently in an effort to reduce general salt intake. The recommended baker’s percent changed, therefore, from 2% to 1% - this means that for 1000 g flour, or 100% flour, we would use 10 g or 1% of salt. I have seen recipes go up to 1.5% and you might see 2% used in older recipe books, but I just generally prefer to slash salt use as much as possible.  


Lastly, we can move on to yeast, which is a little more tricky to work out percentages as we can use one of three yeasts for baking: dried, fresh or natural.  For each of these different yeasts we’ll need a different baker's percent. Dried yeast is strong and works quickly, so we just need 1% of yeast - so for every 1000 g of flour, we’d use 10 g. Fresh yeast is a little bit slower than dried yeast, so we’d use 2%, or 20 g per 1000 g flour. 


Sourdough starters and levens are a little bit more intuitive and take much longer to do their thing. I would generally use 10% of a levain or a sourdough starter, so 100 g per 1000 g flour but I have seen recipes which can call for up to 200 g or 20% of the recipe. 


How to make the calculation


To recap, the Baker’s Percent equals: 


100 % flour - 

60 - 100 % hydration - which could be water, or milk or oil - anything liquid 

1 % salt - though you might see as much as 2% in some recipes

1 % dried

2% fresh

10% natural, though you could see up to 20% in some recipes. 


So if we have 1000 g flour, this would equate to 100% 

600 g - 1000 g hydration

10 g salt

10 g dried yeast


20 g fresh yeast


100 - 200 g natural yeast (levens may vary)


If we want to use 500 g of flour, then that would still represent 100% of our recipe so the amount of each other ingredients would be 


300 g - 500 g hydration

5 g salt

5 g dried yeast


10 g fresh yeast


50 - 100 g natural yeast


And so on and so forth - if you aren’t so confident with working out percentages and you want to make a loaf of bread that isn’t as straightforward as just using a nice round number of flour.  For example, if you want to use 375 g of flour and you aren’t sure how to do that, here’s a link to a baker’s percent calculator. 


How does the percentage change in difference recipes?


The most common cause for change in your Baker’s Percent will be flour and hydration - as you bake more, you will learn more about the properties of different flours. As I have mentioned before, rye isn’t the thirstiest of flours and I’ve often baked with just 68% hydration for some rye recipes. You might need 80% for wholemeal and I generally use 75% for strong white. The more you bake, the more these properties will become part of your repertoire. 


Why do we use the Baker's %?

1. It’s a really useful tool for scaling up and scaling down bread making recipes because the ratio stays the same no matter the size of the batch of dough. 


2. It’s a good way of telling other bakers what the dough or bread is like.

Perhaps you could give your baker chums little insights into how you made that delicious piece of toast that they’re eating by saying something like: ‘why, the delicious piece of toast has a 92% hydration using 50% strong Canadian white bread flour and 50% wholemeal…’ We use the percent, therefore to communicate with other bakers and understand what our bread might be like. 


3. We can also make mental notes about our recipes.

If you’re trying out a new recipe and something doesn’t go quite right, refer back to the baker’s percent and change one of the elements. If I am baking with a strong, white bread flour and I use 72% hydration and my bread doesn’t really rise brilliantly, I could maybe think about increasing the percentage of water and treating it like a biology experiment to see what effects this has on my next loaf. 

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