Sourdough Starter Feeding Calculator

Feeding your sourdough starter: ratios that work

A sourdough starter is a living culture of wild yeast and lactic bacteria, so it has to be fed fresh flour and water on a regular schedule to stay healthy. Those feedings get written as a starter : flour : water ratio by weight. The maintenance default is 1:1:1, say 50 g of starter, 50 g of flour and 50 g of water, and it suits a starter kept at room temperature and used every day or two. At 24–26 °C it usually doubles in 4 to 6 hours. If the starter lives in the fridge, or you just want to slow it down, switch to a 1:5:5 feed (10 g starter + 50 g flour + 50 g water). That stretches the cycle out to 10–12 hours and gives you a milder, less acidic levain.

Common uses

• Home bakers who keep a daily sourdough going.
• Artisan bakeries scaling up levain for the next morning's bake.
• Pizza makers who build a Neapolitan-style levain the night before.
• Brazilian padaria viva projects that keep their fermento natural alive all year.

FAQ

How do I know the starter is ready to bake with? It should have at least doubled, look domed and full of bubbles, and pass the float test, where a spoonful dropped into water floats instead of sinking.

1:1:1 or 1:5:5, which should I use? Go with 1:1:1 when you bake often and keep the starter at room temperature. Reach for 1:5:5 when it's stored in the fridge, or when you need to calm down a starter that has turned too sour.

Why does the ratio matter? The more fresh flour you give per unit of starter, the more food the culture has to work through. Acid builds up more slowly, and the whole fermentation runs longer and calmer.