Work out the flour and water to add when feeding your sourdough starter at a set ratio.
Usage Tip
Discard down to your starter weight before feeding to keep quantities manageable.
Total Starter
— g
After feedingTHE MATH
flour = starter × ratio · water = starter × ratio
A 1:2:2 feed adds two parts flour and two parts water per part of starter.
Higher feed ratios slow fermentation and suit warm kitchens or longer waits.