Work out sourdough starter feeding instantly with clear inputs, formula shown and shareable results.
A feed is expressed as starter : flour : water parts, so the flour and water added are the kept starter weight multiplied by their respective ratios, assuming the kept starter is itself at 100% hydration. Feeding by ratio rather than by eye keeps the acidity and rise time predictable, which is what makes a starter reliable enough to schedule a bake around.
Feed quantities
flour = starter x flour parts; water = starter x water parts
Resulting hydration
hydration % = total water / total flour x 100
flour = starter x flour parts; water = starter x water parts. A feed is expressed as starter : flour : water parts, so the flour and water added are the kept starter weight multiplied by their respective ratios, assuming the kept starter is itself at 100% hydration.
Feeding by ratio rather than by eye keeps the acidity and rise time predictable, which is what makes a starter reliable enough to schedule a bake around.
Enter starter you are keeping, flour parts per part of starter, water parts per part of starter. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.