Sourdough starter feeding calculator

A feeding ratio is the proportion of kept starter to fresh flour to fresh water, written starter : flour : water. Enter how much starter you are keeping and pick a ratio to get the exact grams of flour and water to add. A 1:5:5 feed keeping 20 g means adding 100 g flour and 100 g water.

Starter you are keeping (g)Ratio (starter : flour : water)

Add flour: 100 g
Add water: 100 g
Total fed starter: 220 g

A bigger ratio (more flour and water per part of starter) ferments slower, which suits a warm kitchen or a longer gap between feeds.

Which ratio should you use

A smaller ratio like 1:1:1 ferments fast and peaks in a few hours, which suits same-day baking or a cool kitchen. A larger ratio like 1:5:5 has more fresh food per part of starter, so it ferments slower and holds longer before it needs feeding again. Match the ratio to your schedule and your room.

Ratio and temperature work together

Temperature is the other lever. A warm kitchen speeds everything up, so a bigger ratio buys you time; a cool kitchen slows things down, so a smaller ratio keeps the culture active. See the fermentation by temperature estimator and the guide on how to feed a starter for the full picture.

Feed on schedule, automatically

Banneton remembers your ratio, tracks every feed, and reminds you when each starter is due.

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