For the full beginner system, including starting, feeding, storing, and troubleshooting, use our complete sourdough starter guide.

How to Feed Your Sourdough Starter: Complete Beginner Guide

Feeding your sourdough starter means discarding a portion of it, then adding fresh flour and water so the wild yeast and bacteria have new food to consume. That's the whole concept. Most beginners overcomplicate it — or worse, they underfeed and wonder why their bread is flat. At room temperature (around 70–75°F), a healthy starter needs feeding every 12 to 24 hours. Get the rhythm right and the rest of sourdough baking opens up fast.

What "Feeding" Actually Does to Your Starter

Your starter is a living colony — wild yeast and lactic acid bacteria working together in a flour-water environment. Every time they eat, they produce carbon dioxide and organic acids. The CO2 makes your bread rise. The acids give it flavor.

The problem is they eat everything. Within 12 to 24 hours at room temperature, they've burned through the available sugars and started to slow down. Hooch — that grayish liquid — forms on top. That's not mold. It's a sign your starter is hungry, not dead.

Feeding refreshes the food supply. The discard step keeps the population manageable and the acidity from getting so high it inhibits fermentation. Skip it and you end up with a sluggish, overly sour culture that won't give you lift.

What You Need Before Your First Feeding

You don't need much. A kitchen scale is the one thing I'd call non-negotiable — measuring by volume is inconsistent enough to cause real problems. A 1-quart jar works well. Something with straight sides so you can track the rise.

For flour: unbleached all-purpose or bread flour. Both work. Whole wheat or rye can accelerate activity because they carry more wild yeast on the bran, but they're not required. Stick to one flour until your starter is stable, then experiment.

Water should be room temperature and unchlorinated if possible. Chlorine can suppress microbial activity. I use filtered water, but I've also just left tap water in an open pitcher for 30 minutes and gotten the same result.

The Basic Feeding Ratio (And When to Change It)

The standard ratio is 1:1:1 — one part starter, one part flour, one part water by weight. So 50g starter, 50g flour, 50g water. That's your baseline.

A 1:1:1 ratio at 72°F will peak in roughly 4 to 8 hours. If your starter is peaking too fast — doubling in 3 hours and then collapsing before you can use it — increase the ratio to 1:2:2 or 1:5:5. More food means a slower, more controlled rise.

If your starter is sluggish and barely moves after 10 hours, stick with 1:1:1 and feed more frequently. Twice a day for a few days usually fixes it. Our sourdough starter feeding calculator takes the guesswork out of ratios if you're working with different quantities or temperatures.

Step-by-Step: How to Feed Your Starter

Here's exactly how I do it — no ambiguity.

• Step 1: Take your starter out of the fridge (or off the counter). Note what it smells like — yeasty and slightly tangy is good. Sharp like acetone means it's overdue.
• Step 2: Discard all but 50g. Put the discard in a separate container — you can use it for pancakes, crackers, or flatbread. Don't throw it away.
• Step 3: Add 50g of flour and 50g of room-temperature water to the 50g of starter.
• Step 4: Stir vigorously until fully combined. No dry flour streaks. Some people mix in the jar, I use a small bowl and then scrape back in — either works.
• Step 5: Mark the level on your jar with a rubber band or tape. This is how you track the rise.
• Step 6: Cover loosely (not airtight) and leave at room temperature.
• Step 7: Check at 4, 6, and 8 hours. A healthy starter doubles — sometimes more — and shows a domed top at peak. That's when it's ready to bake with.

That's it. Fifteen minutes of actual hands-on time, most of which is waiting.

How Often to Feed — The Real Answer

Counter storage means feeding every 12 to 24 hours. Fridge storage means once a week. Those are the two modes most home bakers operate in.

If you bake twice a week or more, keep it on the counter. If you bake on weekends, keep it in the fridge and pull it out 24 hours before you need it for a feeding or two to wake it back up.

A starter that's been in the fridge for 7 days isn't dead — it's dormant. Feed it at room temperature and it'll show signs of life within 6 to 12 hours. If it's been in there for 3 weeks or longer, give it 2 to 3 consecutive feedings before you trust it to leaven bread.

I've revived starters that sat untouched in the back of my fridge for six months. They smelled terrible. They bounced back. Don't panic.

Signs Your Feeding is Working (And Signs It Isn't)

A fed starter that's active will double in size within 4 to 8 hours at 72–75°F. It'll have visible bubbles throughout — not just on top. The smell shifts from flat and floury right after feeding to pleasantly yeasty and tangy at peak.

The float test (drop a small spoonful in water — if it floats, it's active) is a useful rough check. It's not perfect, but it's fast.

Red flags: no movement after 12 hours at room temperature, pink or orange streaks (discard immediately — that's contamination), or a smell like nail polish remover that doesn't improve after feeding. If something seems off, our sourdough starter troubleshooter covers the most common problems and how to fix them.

The Discard: Stop Wasting It

Discard gets a bad reputation. It sounds like waste. It isn't.

Unfed discard — starter that's past its peak — has plenty of flavor and enough residual leavening power for quick breads, pancakes, waffles, crackers, and pizza dough. I keep a second jar in the fridge specifically for discard accumulation. It builds up over the week and I bake with it on weekends.

The only time discard is truly unusable is if it's moldy or contaminated. Gray liquid (hooch), strong smell, or separation — all fine. Fuzzy growth in any color other than starter-tan — toss it.

Temperature Changes Everything

Your kitchen temperature has more effect on your starter than almost anything else. At 65°F, a fed starter might take 10 to 12 hours to peak. At 80°F, that same starter peaks in 3 to 4 hours. Same flour. Same ratio. Same starter. Just different temperature.

In winter, I put my starter on top of the fridge where it's slightly warmer, or near (not on) the oven when I'm baking. In summer, I feed in the evening so it peaks overnight when the kitchen is cooler.

If you want to get precise about it — and I do, when I'm baking something I care about — use a probe thermometer to know your starter's actual temperature. Feed times based on room temperature estimates are rough at best.

Frequently Asked Questions

How do I know if my sourdough starter is ready to use after feeding?

Your starter is ready when it has doubled (or more) in volume, shows bubbles throughout — not just on top — and has a domed or slightly convex top surface. This is called "peak activity." At 72–75°F with a 1:1:1 feeding ratio, that's typically 4 to 8 hours after feeding. Use it at or just before peak for maximum lift. If you've missed the window and it's already collapsed, just feed it again and wait.

Can I feed my starter without discarding first?

Technically yes, but you shouldn't make a habit of it. Without discarding, you're continuously adding flour and water to a growing volume of starter. After a few feedings, you'd have gallons of the stuff. More practically, skipping the discard means the acidity builds up over time, which weakens the yeast activity and produces increasingly sour bread. The discard step resets the ratio of microbes to food and keeps the culture healthy.

What's the best flour to use for feeding a sourdough starter?

Unbleached all-purpose flour is the most reliable everyday choice — it's consistent, widely available, and produces a predictable starter. Bread flour has more protein and can give you a slightly more active culture. Whole wheat and rye flour accelerate fermentation because of the extra wild yeast and nutrients in the bran, so they're useful for troubleshooting a sluggish starter. Bleached flour is the one I'd avoid — the bleaching process can inhibit microbial activity.

My starter smells like alcohol or nail polish remover. Is it ruined?

No — that smell means your starter is overly hungry and has over-fermented. The acetic acid content has spiked. Feed it immediately with a 1:2:2 ratio (50g starter, 100g flour, 100g water), let it sit at room temperature, and check it in 8 hours. In most cases, one or two feedings brings it back. If the smell doesn't improve after three consecutive feedings at room temperature, run through our sourdough starter troubleshooter for a more detailed diagnosis.

Ready to start? The Mother is a centuries-old heritage culture that arrives pre-fed and active.

Smelling something sharp? If your starter smells like acetone or nail polish, that’s a specific (and fixable) signal — here’s exactly what it means and the one fix.