StarterFeedingMaintenanceWild Yeast
How to Feed a Sourdough Starter (Ratios, Timing)
8 min read
Beginner
ArtisanCrustLearn how to feed a sourdough starter by weight: 1:1:1 vs 1:5:5 ratios, how often, fridge vs counter, and how to read the hunger signs.
ArtisanCrustYou open the jar, spoon in flour and water exactly like the recipe said, and an hour later it has done precisely nothing. Flat. Sullen. Meanwhile a friend's starter, same age, is climbing the sides of its jar like it has somewhere to be. The difference isn't luck or some secret strain. It's the feed.
Most people think feeding is just refilling the pantry. Hungry culture, add food, done. That's half the story, and the half that gets skipped is the one that matters.
When your starter sits between feeds, the Wild Yeast and the Lactic Acid Bacteria (LAB) keep eating and keep producing acid. The pH drops, often down to around 3.5. That acidity is a fence that keeps mold out, but past a point it also turns on the culture itself. The yeast slows, gas production stalls, and the whole jar goes quiet and sour. The food running low is real. The acid building up is the bigger brake.
So here's what a feed really does: the fresh flour brings new sugars, yes, but the fresh water and flour together dilute the acid. The pH climbs back toward a friendly 4.5 to 5.5, the yeast wakes up, and the rise begins again. You're not topping off a tank. You're resetting a chemical clock. Once that clicks, every ratio decision below stops being arbitrary.
A feeding ratio is written as three numbers: parts of existing starter, parts of fresh flour, parts of fresh water. So 1:1:1 means take 50 g starter, 50 g flour, 50 g water. The numbers aren't a flavour preference. They're a timer.
A small feed reaches peak fast and starves fast. A big feed takes longer to peak and stays usable longer. Here's how the three common ratios actually behave at a normal room temperature of 22 to 24 °C:
1:1:1 peaks in roughly 4 to 6 hours. It's the workhorse for same-day baking and for daily counter maintenance. Quick, predictable, hungry again by evening.
1:2:2 peaks in about 6 to 8 hours. A gentle stretch. Good when you want a morning feed to be ready by late afternoon without babysitting.
1:5:5 peaks in roughly 8 to 12 hours. This is your overnight build and your "I want to feed less often" ratio. The big dilution buys time, so a 1:5:5 feed before bed is ripe and waiting when you wake up.
After about eighty maintenance cycles in my own kitchen, I've landed on a simple habit: 1:1:1 when I'm baking that afternoon, 1:5:5 the night before when I want to sleep in. Same starter, two timers.
This is the one rule with no exceptions. Feed with a digital scale, in grams. A cup of flour might weigh 120 g one day and 150 g the next depending on how packed it is, while a cup of water is always close to 236 g. Measure by volume and your hydration lurches around every single feed, so your starter behaves differently each day for reasons you can't see.
Put the empty jar on the scale, hit tare, and weigh each addition in. Old starter, then flour, then water, taring between each. Thirty seconds of weighing buys you a starter that does the same thing every time, which is the whole point of having one.
Where you keep the starter decides how often you feed it, because temperature is the throttle on the entire culture.
On the counter at 20 to 24 °C, the culture runs at full speed and burns through a feed in well under a day. If you bake often, keep it here and feed once or twice daily at 1:1:1. It'll always be close to ready.
In the fridge at 4 to 6 °C, the Wild Yeast nearly stops and the LAB slow to a crawl. A fridge starter only needs feeding about once a week. Pull it out, let it warm up, discard down, give it a strong feed (1:5:5 works well), let it peak for an hour or two on the counter, then return it to the cold. If you bake weekly or less, this is the low-effort path, and it's exactly the maintenance routine that takes over once you've finished building a starter from scratch.
There's a difference between maintaining a starter and building a levain to bake with. Maintenance keeps a small mother culture alive with minimal flour. A levain build is when you take a spoonful of that mother the night before baking and feed it up to the exact amount your recipe needs, so it peaks right when you want to mix. Keep the two jobs separate and you waste almost no flour.
Here's the routine I'd hand a friend who just finished their first starter and doesn't want to think about it too hard:
If you ever stare at a sleepy jar wondering whether to panic, the starter troubleshooting guide walks through every reason a starter goes quiet and exactly how to fix it.
Try baking the Hearty Rustic Sourdough Loaf to see these principles in action.
Use science in your kitchen! Calculate the exact proportions for your levain build in the Lab.
A starter doesn't want more food. It wants the right amount, at the right time, measured the same way every day. Once you stop guessing at cups and start matching the ratio to your schedule, the jar stops being a mystery and becomes a tool you can set like an alarm clock. Feed it like you mean it, and it'll never let you down on bake day.
Look for visual cues: the dough has increased by about 30-50% in volume, the edges are domed against the bowl, and it "jiggles" elastically when shaken. Tiny air bubbles should be visible just under the surface.
Bacteria produce too much acid, which begins to break down the gluten network. The dough loses its structural integrity, becomes sticky, and will "pancake" in the oven instead of showing a strong oven spring.
Higher temperatures favor lactic acid bacteria but also accelerate acetic acid production if the starter over-matures. In the heat, the fermentation "gas pedal" is floored, making it easier to overshoot the optimal flavor profile.