Baker's percentages and hydration percentages are two math concepts that are helpful when baking bread. Understanding these concepts allow you to become more flexible and creative with your dough recipes, resulting in you being able to make practically anything with your sourdough starter. I love math and when I learned about bakers percentages and hydration levels, it was an epiphany.
Bread doughs are made up of dry ingredients (usually some type of flour), a liquid (usually water), salt and "inclusions" such as seeds, nuts, dried fruit etc.
A baker's percentage is the ratio of a particular ingredient, relative to the total weight of the flour because flour is the universal and most prevalent ingredient.
Why use baker's percentages?
Using baker's percentages allows you to scale up or down the recipe depending on your needs but keeping the correct proportions as percentages in mind is key. It also allows you to develop your own recipes based on basic bread formulas.
Calculating the percentage of an ingredient.
As mentioned earlier, a baker's percentage is the ratio of a particular ingredient, relative to the total weight of the flour because flour is the universal and most prevalent ingredient. This is how you would calculate the percentage of a particular ingredient:
ingredient percentage = (total weight of ingredient/total weight of flour) x 100
For my basic sourdough bread recipe, here is the formula:
700 grams water (80 degrees-lukewarm)
40 grams boiling water
200 grams levain
800 grams bread flour
200 grams wheat flour
20 grams salt
800 + 200 = 1000
700 + 40 = 740
Note. The total flour will always add up to 100%. The individual ingredients will not add up to 100% because it is a ratio of the flour and not a ratio of the entire recipe.
So, armed with this understanding of baker's percentages, you now have the flexibility to change the amounts of ingredients. For example, you only have a limited amount of bread flour but you're dying to make bread, you can use your ratios to determine the amounts of the other ingredients!
The hydration percentage is ratio of water to flour. This percentage gives you an idea whether the dough is going to be very wet or dry. In the above example, the hydration percentage was 74%. The hydration level affects the crumb of the bread. According to Baking 911,
Bread can be classified according to three categories based on hydration: stiff, standard or rustic.
BREAD TYPE AND CRUMB
50 to 57
|Yields dense crumb in breads such as bagels, pretzels|
Bagels (50 to 57% hydration) are one of the least hydrated doughs and are extremely stiff. This means that they need a ton of kneading to get all the flour incorporated and gluten developed; it also means that they are not sticky at all in dough form.
58 to 65
|Yields a denser, closed crumb, in breads such as sandwich bread, rolls, French and other European breads|
Many formulas, such as white sandwich bread, French bread, and challah, use around 57 to 65% hydration. The dough starts to be a bit more tacky, but also more extensible. These doughs can hold their shape well, but also allow for a greater volume in proofing (rising).
65 to 80 or more
|Yields an airy crumb and large, irregular holes, in breads such as ciabatta, focaccia, pizza|
On the higher end of the spectrum you have breads like focaccia and ciabatta, which could be 65 to 80% or more hydrated. These doughs are extremely sticky. Kneading does not usually work on these doughs, and instead techniques used are stretch and fold or just letting the dough develop the gluten over a long period of time on its own (no kneading).
These doughs need careful shaping. They might need a bit more bake time than usual to prevent the inside from being gummy.
Different types of flour absorb water differently because of the amount of gluten protein. You may need to adjust dough consistencies; hydration with one flour at 75% may need to be adjusted to 73% or 77% when using a different brand or type.
Now that you understand baker's percentages, you can understand why using metric measurement is much easier to work with than cups and teaspoons. However, for home baking, some ingredients such as 1/4 teaspoon of something, doesn't register on a scale so it may not appear as a metric measurement.
The lower the hydration level, the easier it is to shape and score your dough, but your bread will be drier. If you are adding seeds to your bread, those seeds are usually soaked the night before with a 100% hydration level except for Chia Seeds. See Chia Seed Bread Recipe