Once a starter exists, learning how to feed sourdough starter is the whole craft: everything about your bread's rise and flavor traces back to when you fed the jar, how much, and at what temperature. The good news is that a starter is far harder to kill than the internet suggests. The frustrating news is that most feeding advice gives you a fixed schedule when what you actually need is to read the jar, because a starter at 68°F and one at 80°F on the same feeding are hours apart. This guide covers the ratios and what each is for, discard, how to tell peak from collapse, what hooch means, the fridge routine for occasional bakers, how to revive a neglected starter, and the test that tells you it's ready to raise bread. If you're still building one from scratch, our <a href="/articles/how-to-make-sourdough-starter">sourdough starter guide</a> comes first.
Step-by-step
Understand the ratio: starter to flour to water, by weight
A feeding ratio is written starter:flour:water, always by weight. 1:1:1 means 50 g of starter gets 50 g flour and 50 g water; 1:5:5 means 20 g of starter gets 100 g flour and 100 g water. Volume measures are useless here because a cup of starter can weigh anything depending on how gassy it is, which is why a <a href="/articles/best-kitchen-scale">kitchen scale</a> with a tare button is the one tool you can't skip. Lower ratios like 1:1:1 give the yeast a small meal relative to their population: fast peak, roughly 4 to 6 hours at room temperature, and a more sour flavor. Higher ratios like 1:5:5 or 1:10:10 dilute the culture into a big meal: slower, 8 to 12 hours, milder, and better suited to warm kitchens and overnight schedules. Both work. Pick the one whose timing fits your day, and stick with it long enough to learn its rhythm. Changing ratios every day is the fastest way to lose track of what your starter is actually doing.
Discard first, then feed — and keep the discard
Before every feed, remove all but the amount of starter your ratio calls for. This isn't waste; it's the only way to keep the math from spiraling. A 1:1:1 feed with no discard means the jar triples each time, and a starter that's mostly old, acidic starter is sluggish because the acid it produced is suppressing the yeast you're trying to encourage. Take the discard out with a narrow jar spatula, scraping the walls as you go so nothing dries into a crust, then add flour and water to what's left and stir until no dry flour remains. The discard goes in a lidded container in the fridge, where it keeps for a week or two for pancakes, crackers, and flatbreads. Use the same flour type at each feed unless you're deliberately transitioning; switching from whole wheat to white or back changes the timing for a few feeds while the culture adjusts.
Time it by temperature, not by the clock
Every schedule you read online assumes a kitchen around 75°F. At that temperature a 1:1:1 feed peaks in roughly 4 to 6 hours. At 65°F it may take 10 or 12; at 82°F it could be done in 3 and collapsing by 5. That's why a strip thermometer on the jar, or a proofing box that holds a set temperature, changes feeding from guessing to scheduling. If your kitchen runs cold, find a warm spot: the oven with only the light on, the top of the fridge, or a cooler with a jar of hot water. If it runs hot, feed at a higher ratio like 1:5:5 to slow things down, or use cooler water. Noting the jar temperature alongside the rise time for a week gives you a personal chart that beats any generic schedule. The starter doesn't care what time it is. It cares whether it has eaten and how warm it is, and feeding when it's ready rather than at a fixed hour is the whole secret.
Read the jar: peak, collapse, and hooch
Right after feeding, mark the level with a rubber band or the jar's feeding band. Over the next hours the starter rises, domes, and holds; that dome is the peak, when the yeast population is at its most active and the starter smells pleasantly yeasty and tangy. Then the surface flattens, the center sinks, streaks appear down the inside of the glass, and the smell sharpens toward vinegar or acetone. That's collapse: the food is gone. A starter that's gone well past collapse separates and grows a layer of dark liquid on top called hooch, which is alcohol, a hunger signal and not spoilage. Pour it off or stir it in (it adds sourness), then feed. A light grey skin on top of a fridge starter is the same story: scrape it off and carry on. The only reasons to throw a starter out are fuzzy mold, pink or orange streaks, or a smell that's genuinely rotten rather than sharp. A grey, sour, deflated starter is just hungry.
Room temperature vs the fridge: choose a routine you'll keep
If you bake several times a week, keep the starter on the counter and feed it once or twice a day, timed to peak when you plan to mix dough. If you bake weekly or less, the fridge is the honest answer. Feed the starter, let it sit at room temperature for an hour or two until it's just starting to rise, then refrigerate; cold slows fermentation to a crawl, so that meal lasts a week or more. Once a week, take it out, discard down, feed, let it start rising, and return it. Don't seal the lid airtight in either case; gas needs to escape. A neglected fridge starter will develop hooch and a grey skin after a few weeks, which looks alarming and means nothing. A starter kept this way for months is routinely fine once it's had a few feeds. Before a bake, give a fridge starter two or three room-temperature feeds to bring it back to full strength.
Revive a neglected starter with several small, warm feeds
A starter that's sat in the fridge for months, grown a thick layer of hooch, and gone grey and smelling of nail polish is almost always recoverable. Pour off the liquid and any dark or dry crust, and take a small spoonful of the paler starter underneath, about 20 g. Feed it 1:1:1 with a bit of whole wheat or rye in the flour, since whole grains carry more food and microbes, and keep it somewhere around 75-80°F. Feed every 12 hours, discarding down each time. Day one usually does little. By the second or third day you should see bubbles and rise; by the fourth or fifth it should be doubling reliably again. If a week of this produces nothing at all, the starter is dead, which is rare, and you're better off starting fresh than continuing to nurse it. Patience is the whole method here; a revival that looks hopeless on day two is usually thriving by day four.
Know when it's ready to bake, and adjust for stiff starters
A starter is ready to raise bread when it predictably doubles or triples within 4 to 8 hours of a feed and is used at or just before its peak. Doubling that happened once isn't enough; you want it to happen the same way two or three feeds in a row. The float test, a spoonful dropped in water, is a rough confirmation, not a substitute. Use the starter when it's domed and full of bubbles, not after it's fallen, since a collapsed starter has spent its leavening power and will give you a slow, sour, flat loaf. If you keep a stiff starter, one fed at 50-60 percent hydration rather than 100, expect it to rise more slowly, taste less sour, and keep longer between feeds in the fridge; the ratios above still apply, just with roughly half the water, and it's worth mixing with a stiff spatula rather than a spoon. For baking it in the right vessel, see <a href="/articles/what-size-dutch-oven-for-sourdough">what size Dutch oven for sourdough</a>.
Recommended Gear
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Premium Pro Sourdough Starter Jar Kit, 40oz Wide Mouth with Feeding Band and Thermometer
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Feeding a starter well comes down to two measurements: how far it rose and how warm it is. This 40-ounce jar puts both on the glass, with a feeding band to mark the post-feed level and a strip thermometer so you know whether to expect a 4-hour peak or a 12-hour one. The wide mouth makes discard-and-feed a one-spatula job.
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U-Taste Silicone Jar Spatula for Sourdough Starter
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A narrow, long-handled silicone spatula is the tool that stops starter crusting up the jar walls, which is where the dried rind and the off smells come from. It reaches the bottom corner of a tall jar, scrapes the sides clean after each feed, and mixes flour into a stiff starter without bending.
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Folding Proofer Folding Bread Proofing Box with Temp Control & 48H Timer
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Temperature is the variable that makes starter feeding unpredictable, and a proofing box removes it. Set 76-78°F and every feed peaks on the same schedule whether it's January or July; it also handles bulk fermentation and final proofs. Folds flat, which is the only reason it's practical in a normal kitchen.
Check Price on Amazon →Frequently Asked Questions
How often should I feed my sourdough starter?
At room temperature, once or twice a day, ideally timed so you feed it just after it peaks and starts to fall. In the fridge, once a week is enough: take it out, discard, feed, let it start rising, and put it back. The real answer is by temperature rather than by clock, since a starter in a warm kitchen can need feeding twice as often as one in a cool one.
What is the best feeding ratio for sourdough starter?
1:1:1 by weight is the standard for daily maintenance and gives a 4-6 hour peak at room temperature. 1:5:5 or higher is better for warm kitchens, overnight feeds, or when you want a milder, less sour starter, because the culture takes longer to eat through the larger meal. There's no single best; choose the ratio whose timing fits when you plan to bake, and keep it consistent so you learn how your starter behaves.
Do I have to discard sourdough starter before feeding?
Yes, unless you're deliberately building up a large amount for a big bake. Without discarding, the jar grows exponentially and becomes mostly spent, acidic starter that suppresses the yeast. Discard down to the amount your ratio needs, then feed. The discard isn't garbage; refrigerate it for pancakes, waffles, and crackers within a week or two. Discarding also keeps the jar from overflowing and keeps the flavor balanced.
What does hooch on sourdough starter mean?
That grey or dark liquid on top is alcohol produced by a hungry starter after it's exhausted its food. It's a feeding signal, not spoilage. Pour it off for a milder flavor or stir it in for a tangier one, then feed, and feed more often or at a higher ratio going forward. Only fuzzy mold, pink or orange coloring, or a genuinely rotten smell mean the starter should be thrown out.
How do I know when my sourdough starter is ready to use?
When it reliably doubles or more within 4 to 8 hours of feeding, several feeds in a row, and is domed and bubbly at its peak with a pleasant yeasty, tangy smell. Use it at that peak, not after it has fallen. A fridge-kept starter usually needs two or three room-temperature feeds to get back to that strength before a bake. The float test is a rough confirmation, not a substitute for watching the rise.
Can I feed my sourdough starter with a different flour?
Yes. Starters adapt to all-purpose, bread, whole wheat, rye, and spelt within a few feeds. Whole grain flours feed the culture more richly and speed it up; white flour gives a milder, more predictable starter. Expect timing to shift for two or three feeds after a switch. Adding 10-20 percent rye or whole wheat to each feed is a common way to keep a white-flour starter vigorous without changing its character much.
Can you overfeed a sourdough starter?
Not in a harmful sense, but a feeding ratio that's too high for the temperature, say 1:10:10 in a cool kitchen, dilutes the culture so much that it barely rises before the next feed and never builds population. If a starter seems sluggish after high-ratio feeds, drop back to 1:1:1 or 1:2:2 for a few days and keep it warm. The opposite problem, underfeeding, shows up as fast collapse, hooch, and a harsh smell, and it's far more common than overfeeding.
Want to dig deeper? See our guides to How to Make a Sourdough Starter, What Size Dutch Oven for Sourdough?, Best Kitchen Scale (2026), and Best Dutch Oven (2026).