When you look at a sourdough recipe, you make notice percentages associated with each ingredient. This is the baker’s percentage. It is basically the percentage of each ingredient used relative to the flour. The quantity of flour is usually 100%, unless otherwise stated.
The reason some recipes will give baker’s percentages is so you can easily scale the recipe can be scaled up and down. If you know the percentage of each ingredient, you can scale the recipe to any quantity of flour.
For example, if you look at my basic sourdough bread recipe, all the percentages are based off of 300g of flour. This yields a loaf that is just shy of 500g. I would consider this a medium sized loaf. But, if you wanted a larger of smaller loaf size, you can determine the quantity of flour you want to use and scale all the other ingredients from there. In your calculations, you may get decimal values, but you can just round to the nearest unit.
Here is how to calculate the quantity of ingredients needed from the percentage provided:
- Determine the quantity of flour you are using in grams or ounces.. This represents 100% and all other calculations are based off it.
- Take the percentage of one ingredient (ex. water) and convert it into a decimal. Ex. 60% becomes 0.60.
- Multiply the decimal value by the quantity of flour. The number you get is the quantity of that other ingredient (ex. water) you need.
- Repeat with the other ingredients in the recipe.
NOTE: if you are altering size of the recipe, you may need to alter cook times to accommodate.