How long does it take to make a sourdough starter from scratch?

Usually 7–14 days. Wild yeast needs time to outnumber the bacteria that dominate the first few days. Some starters are bake-ready by day 7 in a warm kitchen; a cold room can push it past two weeks. Judge readiness by consistent rising, not by the calendar.

What flour is best to start a sourdough starter?

Start with whole-grain flour — whole wheat or rye. The bran carries far more wild yeast and nutrients than white flour, so it kick-starts fermentation fast. After the first few days you can switch to bread or all-purpose flour, or keep a portion of whole grain in each feed for a livelier culture.

Do I have to discard sourdough starter every day?

Yes, once you're feeding daily. Discarding keeps the culture from outgrowing its jar and, more importantly, keeps the acid load low — too much accumulated acid stalls the yeast. Keep 25–50g and remove the rest before each feed. Save the discard for pancakes or crackers rather than binning it.

Why did my starter rise on day 2 or 3 then stop?

That early burst is a false rise driven by Leuconostoc and other bacteria that thrive briefly in fresh flour — not the wild yeast that leavens bread. It's harmless and expected. The starter then goes quiet for several days while the yeast establishes. Keep feeding through the slump; don't throw it out.

Can I use tap water for my starter?

Usually yes. If your tap water is heavily chlorinated it can slow things down — leave it uncovered for an hour or use filtered water. Room-temperature water is best; very hot water can kill the culture.

My starter isn't rising after a week. Is it dead?

Almost certainly not — it's usually too cold or too acidic. Move it somewhere warmer (75–82°F / 24–28°C), switch to feeding twice a day, and add a spoonful of rye or whole wheat. Most 'dead' starters revive within a few days of warm, consistent feeding.

How do I know when my starter is ready to bake with?

It should double in volume within 4-8 hours of a feed, dome at the top, look bubbly and smell pleasantly tangy — and do it three feeds in a row at the same time each day. One good rise isn't enough; you're looking for repeatability before you plan a bake around it.

How to Make a Sourdough Starter From Scratch — Ferment Calculator

Making a sourdough starter from scratch is mostly patience. You mix flour and water, feed it a little every day, and over a week or two wild yeast and lactic acid bacteria from the flour and the air colonise it into a living culture that can leaven bread. No commercial yeast, no special equipment — just a jar and a routine.

What you need

The whole project fits on a shelf. There’s nothing to buy beyond flour.

A jar and a kitchen scale A clear glass jar (500ml–1L) lets you watch the rise; a digital scale in grams is the one tool that actually matters — cups are too inconsistent for a young culture.

Whole-grain flour to begin Whole wheat or rye for the first few days. The bran is loaded with wild yeast and nutrients and gets fermentation going far faster than white flour.

Room-temperature water Filtered or tap. If your tap water is strongly chlorinated, leave it out for an hour first. Never use hot water — it can kill the culture.

Cover the jar loosely — a lid resting on top, or a cloth and rubber band. The culture needs to breathe and to vent gas, so don’t seal it airtight.

Day 1: mix the first batch

Weigh 50g whole-grain flour and 50g room-temperature water into the jar and stir to a thick, lump-free paste. Scrape down the sides, mark the level with a rubber band or a strip of tape, and set it somewhere warm.

Warmth is the single biggest lever you have. Aim for 75–82°F (24–28°C) — on top of the fridge, near (not on) a radiator, or in an oven with only the light on. A cold kitchen doesn’t stop a starter, it just makes everything take longer. Then leave it 24 hours; nothing much happens on day 1.

The daily rhythm: discard and feed

From day 2 onward you repeat one simple cycle once a day, at roughly the same time.

1
Discard most of it Stir the starter down, then keep only about 50g and remove the rest. This feels wasteful but it is essential — it keeps the acid load low so the yeast can thrive.
2
Feed 1:1:1 by weight To the 50g you kept, add 50g flour and 50g water. That is a 1:1:1 ratio — equal parts starter, flour, and water. Stir smooth.
3
Mark and wait Reset the rubber band to the new level so you can see how far it rises, re-cover loosely, and leave it warm for 24 hours.

Around day 3–4, once you see any bubbling, switch to feeding twice a day (morning and evening) to build strength faster. You can move from whole-grain to bread or all-purpose flour now, or keep 10–20% whole grain in each feed for a livelier culture. Save your discard for pancakes, waffles, or crackers rather than binning it.

The day-by-day timeline

Every starter is different, but most healthy ones move through the same three stages. These windows assume a warm spot around 75–80°F / 24–27°C — a cooler room shifts everything later.

Days 1–4 first activity & false rise

Days 4–8 the quiet slump

Days 7–14 real, predictable rising

The most useful thing to know in advance is that progress is not a straight line. A dramatic early rise is followed by a discouraging quiet spell, and then the real culture arrives. Knowing the slump is coming is what stops most people from throwing a perfectly good starter away.

Day 2–4: the false rise (don't be fooled)

Somewhere around day 2 or 3 your starter may erupt — bubbling, tripling, foaming, smelling sweet or faintly cabbage-like. It looks ready. It isn’t.

That burst is Leuconostoc and other bacteria that briefly bloom in fresh flour. They give off gas, so the mix rises, but they aren’t the wild yeast that leavens bread — and they die back as the culture turns more acidic. The tells that it’s a false rise, not the real thing:

A sweet, funky, or cabbage-y smell not the clean, tangy, yeasty aroma of a mature starter.

Runny, foamy, collapses when stirred gas from bacteria rather than a strong yeast structure.

Happens very early (day 2–3) far sooner than wild yeast can realistically establish.

Do nothing special — just carry on with your normal feeds. Keep it warm, feed 1:1:1 twice a day, and let the false rise pass.

Day 4–8: the quiet phase

After the false rise dies down, most starters go quiet — little or no rising, sometimes for several days. This is the single most common point at which beginners give up, and it’s almost always a mistake. The yeast is establishing itself in the background; the lull is a stage, not a failure.

Keep feeding on schedule and hold the temperature up. If a week passes with genuinely no bubbles at all, treat it as sluggish rather than dead:

! Watch for

Too cold — move it somewhere warmer; even 5°F / 3°C can double the timeline
Feeding too little — go to twice-daily 1:1:1 feeds for a few days
White flour only — add a spoonful of rye or whole wheat to reboot it
Chlorinated water — switch to filtered or de-chlorinated water

Signs it's ready to bake with

The real culture announces itself with predictable rising: after each feed the starter climbs and, within a few hours, roughly doubles and domes at the top. When you see that happening reliably, run a quick confirmation:

It doubles on schedule Rises to about twice its fed volume within 4–8 hours, then holds a domed peak before slowly falling.

It smells and looks right Bubbly throughout, with a pleasant yeasty-tangy aroma — like mild yogurt or beer, not sharp or sour-funky.

It does it three feeds running One good rise can be luck. Three consecutive feeds that double at roughly the same time mean the culture is stable and bake-ready.

A quick float test can back this up: drop a small spoonful into water and, if it’s gassy enough, it floats. Treat it as a bonus signal, not the deciding one — consistent doubling is the real test. For the full checklist of what “active” looks like, see the active starter guide.

Keeping it alive once it's established

Once your starter passes the three-feed test, you don’t have to feed it twice a day forever. If you bake often, keep it on the counter and feed once daily. If you bake weekly or less, store it in the fridge and feed just once a week — the cold slows it to a dormant, low-maintenance state.

To bake from a fridge starter, take it out a day ahead, give it one or two feeds at room temperature, and wait for it to peak. From here on, the only real skill is feeding it the right amount at the right ratio.

Try the calculator

Sourdough Feeding Calculator

Exact flour and water for any feeding ratio and jar size, so your starter peaks when you want to bake.

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