Starter

Feeding your sourdough starter: ratios, rhythm and a rest in the fridge

Updated October 2026 · 2 min read

A starter is an undemanding pet: regular flour and water. How much and how often depends on when you want to bake next.

What feeding does

You keep part of the starter, add fresh flour and water, and leave it. The yeasts and bacteria multiply, the starter rises, reaches a peak and falls again once the food is used up.

The ratio

A ratio of 1:1:1 means one part starter, one part flour, one part water, by weight. The more fresh flour relative to starter, the longer it takes to peak. That is how you control the timing.

Ratio	Example	Peaks after about
1:1:1	20 g starter, 20 g flour, 20 g water	4–6 hours
1:2:2	20 g, 40 g, 40 g	6–8 hours
1:5:5	10 g, 50 g, 50 g	10–12 hours

The times apply roughly at 24 °C (75 °F). At 20 °C it takes noticeably longer, at 28 °C it goes faster. A 1:5:5 feed in the evening gives you a ripe starter the next morning.

The rhythm

At room temperature a starter needs feeding once or twice a day. That only makes sense if you bake very often.
In the fridge once a week is enough. Feed it, let it get going for an hour or two at room temperature, then back into the fridge.
Before baking, refresh it once or twice at room temperature. Straight from the fridge it is sluggish.

Catching the best moment

Bake with the starter at its peak or just before: it has roughly doubled, the surface is domed and full of bubbles. If the surface has already sunk and you can see streaks on the glass, the peak has passed. The bread will be a little more sour and rise a little less, but it is not ruined.

Less waste

Keep only as much starter as you need. 20–50 g is enough to build the amount for a bake. Leftovers work well in pancakes, waffles or crackers.

Holidays

A freshly fed starter usually survives two to three weeks in the fridge without trouble. For longer, dry it: spread it thinly on baking paper, let it dry at room temperature, crumble it and store it airtight. To revive it, soak it in water and feed it for a few days.

Common questions

Do I have to discard some every time?

Only if the jar would otherwise keep getting fuller. If you keep small amounts and bake with the rest, you throw away very little.

How much starter do I need for a loaf?

Usually 15–25 % of the flour weight. For a loaf with 500 g flour that is about 75–125 g. Work backwards to how much you need to build the evening before.

Can I bake straight from the fridge?

You can, but the dough will rise more slowly and taste more sour. A refresh at room temperature the evening before or in the morning works better.