Techniques

Sourdough starter feeding schedule, worked back from mix time

A feeding schedule is a promise: the starter will be at its peak at the moment you mix. Everything else, the ratio, the water temperature, the number of feeds, is a way of keeping that promise on a day with a particular room temperature and a particular mix time.

The one number to fix first

Decide when you mix. Everything is counted backwards from there. If the dough goes into the mixer at 06:00, the starter has to peak at 06:00, and a starter that peaked at 03:00 has already begun to collapse and acidify by then. Three hours past peak it still leavens, but the bread will be more sour and the gluten a little weaker.

A starter is at peak when it has risen to its maximum height and the top is just beginning to flatten. Domed and rising, it is young; sunken with a liquid layer, it is past it.

Ratio is a timer

Feeding ratio is written as starter : flour : water. It decides how long the starter takes to peak, because the fresh flour is the food and the old starter is the population that eats it. More food per organism means a longer meal.

A small feed, close to equal parts, peaks in a few hours and turns sour soon after. A large feed, five or ten parts flour to one of starter, takes most of a night and stays mild. Read that the other way round and the ratio becomes a schedule: if you mix at six in the morning, the ratio that peaks in nine hours is the one that lets you feed at nine in the evening and sleep.

The exact hours belong to your starter, your flour and your room. Time one feed of each ratio you use, note the hour it peaks, and you have the only table that matters.

Temperature is the other timer

Every few degrees warmer shortens the time to peak noticeably. Water temperature is the lever you control: in a cold bakery, feed with warmer water; in summer, use cool water or a smaller ratio. Keeping the starter in a proofer at a fixed temperature takes the room out of the equation and makes the schedule the same in January and July.

How much to build

Work out the levain you need from the recipe, then add a margin so you never scrape the jar bare.

1. Levain in the recipe: say 20 percent of 10 kg flour, which is 2 kg of levain.
2. Keep back 100 to 200 g as tomorrow’s seed.
3. Build 2.2 kg. At 1:5:5 that is 200 g seed, 1 kg flour and 1 kg water.

If the recipe needs more levain than one build can produce in the time available, use two stages: a small feed in the afternoon, a larger one in the evening. Two-stage builds also give a milder, more consistent levain, because the seed for the second stage is always young.

A weekly rhythm for a bakery that bakes six days

• Baking days: one feed the evening before, sized for the next morning’s levain, at whichever ratio lands the peak at mix time.
• Rest day: feed once at a large ratio, or refrigerate after a feed. Do not skip; a starter that misses a day in a warm room comes back sluggish for two.
• After the rest day: the first levain may peak later than usual. Allow an extra hour, or feed twice.

The two mistakes that cause most dense loaves

Using the starter too early, when it has not peaked, gives a weak leavening and a long, unpredictable bulk. Using it too late, well past peak, gives sour bread with a tight, gummy crumb because the acids have weakened the gluten. Both are timing faults, and both are cured by choosing the ratio that matches the hour you can mix.

Letting the arithmetic do the work

Your starter’s timing, your room temperature and your mix time are all the inputs a schedule needs. In bakeryOS the recipe knows how much levain it wants and the starter knows its own rhythm, so choosing “mix tomorrow at 06:00” produces the feed times and quantities for each stage. The point is that it is done every day, including the one after the rest day.

Questions bakers ask

How many hours before baking should I feed my starter?

Feed it so it peaks when you mix, not when you bake. How long that takes depends on the feeding ratio, the temperature and how lively the starter is, which is why it is worth measuring once in your own bakery rather than copying a number.

What ratio should I feed my starter?

The ratio is a timer. A small feed peaks fast and turns sour quickly; a large feed takes longer and stays milder. Pick the ratio that lands the peak at the hour you can mix.

Can I keep my starter in the fridge between bakes?

Yes. A starter fed and refrigerated within an hour or two keeps for a week or more. Give it one or two feeds at room temperature before you rely on it for a full bake.

Related

• Preferment: levain, biga, poolish and pâte fermentée explained. A preferment is part of the dough fermented in advance. Levain uses wild yeast; poolish, biga and pâte fermentée use baker's yeast at different hydrations.
• How long to bulk ferment sourdough, and how to tell when it is done. Bulk fermentation is done when the dough has grown 30 to 75 percent, domes at the edges and jiggles as one mass. At 24 to 26 °C that takes four to six hours.
• Why is my sourdough dense? Causes in order of likelihood. Dense sourdough is usually underfermented: the levain was not at peak, or bulk was cut short in a cool room. Weak flour, too much whole grain and rough shaping come next.

Sources: Hamelman, Bread, 3rd ed.; Robertson, Tartine Bread; Gobbetti and Gänzle (eds.), Handbook on Sourdough Biotechnology, Springer 2013. Updated 2026-09-09.