How often should I feed my sourdough starter?
At room temperature: every 12 hours at a 1:1:1 ratio. In the fridge: once a week. Before a bake, bring it out and feed it once or twice until it doubles within 4–8 hours. A starter is far harder to kill than the internet suggests.
The ratio sets the interval
Feeding is not really a schedule — it is a race between how much food you gave the culture and how fast it eats it. Change the ratio and the interval moves with it, which is the single most useful thing to understand about starter maintenance.
At 1:1:1 by weight — equal parts starter, flour and water — a healthy starter at 21–24°C peaks in 4–8 hours and needs feeding again around the 12-hour mark. Feed it at 1:5:5 instead and it will take far longer to exhaust, comfortably 24 hours. Bakers who dislike twice-daily feeding usually just feed at a bigger ratio.
Temperature moves it too, and more than people expect. A starter at 28°C runs perhaps twice as fast as the same starter at 20°C. In a warm kitchen in summer, the 12-hour interval genuinely becomes 8.
Fridge storage is the normal answer for most people
Unless you bake several times a week, keep it in the fridge and feed it once a week. Feed it, let it start to rise at room temperature for an hour or two, then put it away. Cold slows fermentation to the point where a week is a comfortable interval.
A starter left in the fridge for two or three weeks is almost always recoverable. It will have separated, smell sharply of alcohol or acetone, and have a dark liquid layer on top. Pour that off, discard all but a spoonful, feed it, and repeat every 12 hours for two or three days. It usually comes back.
Before baking, plan a day or two of room-temperature feeding. A starter straight from the fridge has plenty of acid and not much gas-producing yeast activity, and bread made with it rises slowly and tastes flat and sour. Two feeds at room temperature restore the balance.
How to tell it is hungry, and how to tell it is ready
- Hungry: it has risen and fallen back, the surface has gone flat or slightly sunken, and there is a layer of grey-brown liquid — hooch — on top. Hooch is alcohol, it is harmless, and it means "feed me", not "throw me out"
- Hungry: the smell has shifted from tangy and yeasty toward sharp, boozy, or like nail varnish remover
- Ready to bake with: it has roughly doubled, the surface is domed and bubbly, and it is at or just before peak. Marking the jar with a rubber band at feeding time is the simplest possible measurement
- Ready to bake with: a spoonful floats in water. The float test is imperfect but a positive result is a good sign
- Not ready: it doubles in 12 hours rather than 6. Keep feeding daily for a few days before blaming the flour
What is actually wrong versus what only looks wrong
Hooch, a strong sour smell, separation, sluggishness after the fridge, and a grey tint are all normal and all fixable with feeding. A young starter that rose dramatically on day two and then went quiet on day four is also normal — that early activity is usually the wrong bacteria, and the quiet period is the culture sorting itself out. Keep feeding.
The genuine problem is mould: fuzzy spots in pink, orange, green or black, or a pink or orange streak. That one gets thrown away, jar and all contents, and started again. Ordinary sourdough smells sour; it should never smell rotten.
The discard is not waste, incidentally. Refrigerated discard keeps for a week or two and makes crackers, pancakes and waffles, which is what most of a maintained starter's output actually becomes.