Baker's Percentages: How To Use Them
April 16, 2019
You may have noticed that for some sourdough bread recipes there are percentages next to the weights or you may have heard someone say that their sourdough bread was "80% hydration". These refer to baker's percentages or baker's math. Baker's percentages are a way to scale up or down sourdough bread recipes easily, and also to use only one unit of measure (like grams) which enables the baker to be more precise.
In Baker's Percentages, flour is always at 100%, and the rest of the ingredients are a percentage of a flour's weight. So if a baker said that they used 1000g of flour and their hydration was at 80%, this means that they used 800g of water in their recipe.
To determine the percentage of the other ingredients in a recipe the formula is as follows:
(weight of ingredient ÷ weight of flour) x 100 = %
Here are the percentages for our Basic Sourdough Boule
1000 grams Flourist Sifted Red Spring Wheat Flour (100%)
875 grams warm water (87.5%)
175 grams sourdough starter (17.5%)
25 grams salt (2.5%)
From this, you can adjust the recipe as needed. If you found that the hydration level in this recipe was too high and difficult for you to work with you may want to adjust the recipe to 80% hydration. To do this you would use the following formula.
weight of flour x percentage of ingredient = weight of ingredient
1000 grams x 80% = 800 grams.
You can also use Baker's Percentages if you only have a certain amount of flour and you want to use it all to make a loaf. It is much easier to do math using percentages than to try any other way. Let's say you only have 750g of flour. Using the recipe for our Basic Sourdough Boule we can create a recipe that would use the entirety of the flour:
750 grams Flourist Sifted Red Spring Wheat Flour (100%)
656 grams water (750 grams x 87.5%)
131 grams sourdough starter (750 grams x 17.5%)
19 grams salt (750 grams x 2.5%)
Sometimes you will see Baker's Percentages used in recipes beyond sourdough bread but this is less common and not widely used.
Find the rest of our sourdough baking resources here.