Sourdough Starter Feeding Calculator

X:Y:Z ratio starter:flour:water. Standard 1:1:1 for daily; 1:5:5 for slower fridge schedule.

Inputs

1:1:1 = use all starter as inoculant. 1:5:5 = use less, slower rise.

Result

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General calculation reads

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How to use this calculator

  • Weigh current starter.
  • Pick ratio (1:1:1 daily, 1:2:2 or 1:5:5 for fridge).
  • Toggle discard if you don't want exponential growth.
  • Mix to ratio; let rise 4-12 hours depending on ratio + temperature.

About this calculator

Sourdough feeding ratios express starter:flour:water by weight. 1:1:1 is the daily-counter standard: equal-mass starter, flour, and water, doubling the starter mass. 1:5:5 is the fridge / slow schedule โ€” less existing starter, more new food, longer time to peak. Higher flour:starter ratios delay peak (more food to consume) and produce a stronger flavor. Discarding before feeding controls the size โ€” without discard, your starter doubles every feed, which gets unwieldy fast.

Frequently asked

Why discard?+
Without it, daily 1:1:1 feedings double mass each time โ€” 25g โ†’ 50g โ†’ 100g โ†’ 200g in 3 days. Discard keeps it manageable.
What ratio peaks fastest?+
1:1:1 at room temp peaks in 3-6 hours. 1:5:5 takes 8-12. 1:10:10 takes 12-24.
Hydration of starter?+
"100% hydration" means equal flour + water by weight. Sticky paste consistency. Some bakers use 60% (stiff starter) for more flavor.
Can I use kitchen scraps as discard?+
Yes โ€” discard makes pancakes, crackers, waffles. Add 1 tsp baking powder to compensate for inactive starter.
How do I know it's ready to bake with?+
Doubled in volume, domed top, light bubbles throughout. Float test: drop a teaspoon in water โ€” should float.

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