Fermento
Hydration
Water weight divided by flour weight, times 100. 350 g of water in 500 g of flour is 70%.
Calculator
Sourdough calculator
Hydration, starter percentage and feeding ratio, by weight. Enter what is in your bowl.
Pick Bread for a dough or Cultures for a feed. The example numbers are a 500 g loaf at 70% hydration.
Salt Percentage
2.50%
Salt percentage relative to vegetable weight
Fermento saves the number with your batch.
Starter percentage
Starter weight divided by flour weight, times 100. 100 g of starter in 500 g of flour is 20%.
Feeding ratio
Starter to flour to water, with the starter as 1. 50 g of starter fed 50 g of flour and 50 g of water is 1:1:1.
In the app
The numbers stay with the loaf
In Fermento each bake keeps its hydration, dough temperature and taste notes, and each starter keeps its feeds. Next time you can see what you did when it went well.
App of the Day
from the creators of 
murmur and 
Layered
Sourdough in Fermento
Questions
How do I calculate sourdough hydration?
Divide the weight of water by the weight of flour and multiply by 100. 350 g of water in 500 g of flour is 70% hydration.
What is a 1:5:5 feeding ratio?
One part starter, five parts flour and five parts water, by weight. 10 g of starter is fed 50 g of flour and 50 g of water.
How much starter goes in a loaf?
It is written as a percentage of the flour. 100 g of starter in 500 g of flour is 20%. The calculator works it out from your own weights.
Sourdough timeline Starter feeding ratios Starters and SCOBYs