Knowing how to feed sourdough starter is what keeps it alive, strong and ready to bake with — it’s the small routine behind every good loaf. Feeding is simple once you understand what it’s actually doing: you’re giving the culture fresh flour and water to eat so the wild yeast stays active and healthy. Here’s how to feed yours, how often, and how to keep it going through everything from a quiet week to a three-week holiday.
(New here? Start with [how to make a sourdough starter] first — this guide is about keeping an established one going.)
What Feeding Actually Does
A starter is a living colony, and like anything alive it needs to eat. The wild yeast and bacteria consume the sugars in the flour, and once they’ve eaten through it, the culture runs out of food, goes hungry and slows down. Feeding resets the clock: you remove most of the old, spent culture and give what’s left a fresh supply of flour and water to grow into.
That’s the whole logic. A well-fed starter is bubbly, active and rising. A hungry one is flat, sluggish and sour. Everything below is just about timing that cycle so your starter is at its strongest when you want to bake.
The Anatomy of a Feed
Every feed has three parts, always in the same order:
- Discard. Remove most of your starter — usually all but a small amount. This sounds wasteful, and we’ll deal with what to do with it below, but it’s essential: it keeps the culture young and stops your jar overflowing.
- Add flour. Fresh flour is the food. White bread flour is the standard for maintenance.
- Add water. Room temperature, to bring it back to a thick, paste-like consistency.
Stir, rest the lid on top, and leave it to rise. That’s a feed.
Feeding Ratios, Explained
A feeding ratio is just the proportion of old starter : fresh flour : fresh water, by weight. It’s the single most useful thing to understand, because it controls how fast your starter ferments.
- 1:1:1 — equal parts. For example, 25g starter, 25g flour, 25g water. This ferments fast and peaks in a few hours. Use it when you’re baking often and feeding daily at room temperature.
- 1:2:2 — one part starter to two parts each flour and water. More food relative to the culture, so it takes longer to peak. Good when you want a stronger rise or a slightly longer gap between feeds.
- 1:5:5 or higher — a lot of food for a little culture. This stretches the time to peak considerably, which is useful before a long rest or when you want to feed once and leave it.
The rule underneath all of them: more food relative to starter means a slower, longer rise. Less food means a faster one. Once that clicks, you can dial your starter’s schedule to fit your day instead of the other way around.
Timing: Feed at the Peak
Here’s the part that matters most for baking. After you feed, your starter rises, reaches a high point where it’s most active and full of gas — its peak — and then slowly falls back as the food runs out.
Bake with it at, or just before, its peak. That’s when it has the most lifting power. For a 1:1:1 feed at room temperature, peak usually lands around 4–6 hours after feeding, though flour and temperature shift that. Watch for it doubling in size with a domed, bubbly top. If it’s risen and started to sink back, it’s past its best — feed it again and wait for the next peak rather than baking with a tired starter.
A simple trick: mark the starter’s level with a rubber band right after feeding, so you can see exactly how far it’s risen.
Don’t Throw Away Your Discard
That spent starter you remove at each feed isn’t garbage — it’s just unleavened fermented flour, and it’s genuinely useful. Keep a jar of it in the fridge and add to it as you go.
Discard is excellent in things that don’t need a rise: pancakes and waffles, crackers, flatbreads, quick breads. It adds a gentle tang and cuts down on waste, which feels a lot better than pouring good flour down the sink. It’s not strong enough to raise a loaf on its own, so keep it for recipes where it’s a flavor ingredient rather than the leavening.
Everyday Maintenance: Counter or Fridge
How you keep your starter depends entirely on how often you bake.
If you bake often, keep it on the counter at room temperature and feed it once or twice a day. It stays active and ready, and you can bake almost any time.
If you bake occasionally, keep it in the fridge. The cold slows the culture right down, so it only needs feeding about once a week. To bake, take it out a day ahead, give it a feed or two at room temperature until it’s bubbly and rising again, and it’s ready. This is how most home bakers keep a starter — awake only when they need it.
Going Away? How to Store Your Starter
A starter is far more resilient than people fear. Here’s how we handle time away, by length:
A few days: do nothing special. Feed it, and either leave it on the counter or pop it in the fridge. It’ll be fine.
Up to about three weeks: feed it well, then put it straight in the fridge. The cold slows it almost to a standstill, and it’ll wait for you. When you’re back, take it out and feed it a couple of times to wake it up. This is what we do for most trips — feed, chill, and forget about it.
Traveling, or want to bake where you’re going: you can take it with you. We pack ours in checked luggage and bake when we land. One thing we’ve learned the hard way: seal it properly. We put ours in vacuum bags and seal them completely airtight — a starter is still alive and slowly producing gas, and with the pressure changes on a flight a loosely closed jar or bag will leak. A fully sealed vacuum bag travels cleanly every time. Checked luggage is also the easy way to do it, since a wet, runny starter carried in your cabin bag can get treated as a liquid at security.
Very long trips, or as a backup: dry it. Smear a thin layer of active starter across a sheet of baking paper, let it dry completely into flakes, and store the flakes in a bag. Dried starter keeps for months, weighs nothing, and revives with flour and water over a few days. It’s cheap insurance — worth doing once so you always have a backup even if your main jar ever fails.
When Your Starter Seems Off
Most problems come down to a hungry or cold starter, and both are easy to fix.
- Weak or slow to rise. Usually underfed or too cold. Feed it more often, move it somewhere warmer, and give it a few days to build strength.
- Very sour, or liquid on top. That liquid is hooch — a sign it’s hungry. Pour it off and feed more frequently.
- Rises then sinks fast. It’s peaking and running out of food quickly. Try a higher ratio (1:2:2) so it has more to eat.
- Sluggish after the fridge. Normal. It just needs a feed or two at room temperature to wake up before it’s bake-ready.
A healthy starter is a hard thing to actually kill. Feed it, keep it warm enough, and it’ll bounce back from almost anything.
One tool worth having
Feeding by weight is what keeps your ratios consistent — eyeballing spoons is where a starter drifts weak or unpredictable.
- A digital kitchen scale — measure your ratios to the gram and your starter stays reliable (the one I actually use)
Sourdough for Beginners · Step 2 of 9