A quiet, seven-to-ten-day process for building a live sourdough starter from scratch — the foundation every recipe on this site is built on. No commercial yeast, no shortcuts, no discard tricks. Just flour, water, and time.
What a starter is
A sourdough starter is a stable, living mixture of flour and water that wild yeast and lactic acid bacteria call home. The yeast came from the flour itself and the air in your kitchen. Once it's established, you feed it fresh flour and water on a regular schedule, and in return it leavens your bread — the same way commercial yeast does, just slower and with more flavor.
You only make a starter from scratch once. After that, a small amount of established starter feeds new dough every time you bake.
Why organic whole wheat
Whole wheat flour is the most reliable way to start and maintain a sourdough starter. The bran and germ carry more of the wild yeast, nutrients, and minerals fermentation needs.
I feed mine with King Arthur Organic Unbleached Whole Wheat Flour — start to finish, forever. It's clean, unbromated, unbleached, and widely available. The organic matters more than the brand; the flour touches the starter's yeast every day, and I don't want spray residue in that loop.
You can switch to all-purpose or bread flour later if you want. Plenty of bakers do. But the whole wheat starter I keep is stronger, more flavorful, and rides through neglect better than an all-purpose one. It's worth staying with.
The one ratio you need: 1:1:1
Every feed after day 3 uses the same math:
Equal weights of starter, flour, and water.
Twenty grams of each. Fifty of each. Whatever you want — the ratio is what matters. This is called a 1:1:1 feed at 100% hydration, and it's the ratio every recipe on this site is built around. When a recipe says "100 g active starter," it means 100 g of a 1:1:1 starter that's at peak.
Learn this ratio once. You won't need another.
What you'll need
- King Arthur Organic Unbleached Whole Wheat Flour — for every feed, day 1 to forever
- Filtered or bottled water — tap water with chlorine can slow or kill wild yeast. Room temperature
- A clean glass jar — quart size, wide mouth, with a loose-fitting lid. Not airtight
- A rubber band or dry-erase marker — to mark the starter's height so you can see it grow
- A kitchen scale — sourdough is weighed, not measured
Optional but helpful: A Brod & Taylor Sourdough Home holds your starter at a steady 73–82°F, which speeds and stabilizes fermentation — especially useful in cool kitchens. Not required. A warm spot on the counter works too. More on hardware over on the kit page.
Day-by-day schedule
Total time: 7 to 10 days from mix to ready-to-bake. Don't rush this. A starter is ready when it's ready, not on a specific day.
Day 1 — Mix
In your clean jar: - 50 g whole wheat flour - 50 g filtered water
Stir with a clean utensil until no dry flour remains. It'll look like thick mud. Scrape down the sides. Mark the height with a rubber band or dry-erase line. Cover loosely and leave on the counter at room temperature (68–75°F).
Nothing will happen visibly today. That's normal.
Day 2 — Wait
Check the jar. You might see a few bubbles. You might see nothing. Either is fine.
Don't feed it yet. The natural yeast is waking up. Feeding too early actually starves it. Leave it alone for 24 hours.
Day 3 — First 1:1:1 feed
You should see bubbles by now — small ones scattered through the mixture, or a slightly domed surface. If you don't, wait another 12–24 hours and check again.
When you see bubbles: 1. Stir the starter 2. Discard all but 50 g 3. Add 50 g whole wheat flour and 50 g filtered water 4. Stir well, mark the new height, cover loosely
This is your first true 1:1:1 feed. Every feed from here forward is the same ratio.
Days 4–7 — Twice-daily 1:1:1 feeds
The starter is picking up speed. Feed it every 12 hours — once in the morning, once at night.
Each feed: 1. Stir 2. Discard all but 50 g 3. Add 50 g whole wheat flour and 50 g filtered water 4. Stir, mark height, cover
By day 6 or 7, you should see the starter roughly double in the 4–8 hours after a feed, then slowly deflate. It'll smell tangy, yeasty, faintly like beer or ripe fruit. That's good.
Days 8–10 — The float test
When your starter is doubling reliably within 4–6 hours of a feed, test if it's ready:
- Feed the starter and wait until it's at its peak (roughly doubled)
- Drop a small spoonful into a glass of room-temperature water
- If it floats, the starter is active enough to bake with
- If it sinks, keep feeding twice a day until it floats
Some starters float by day 7. Some take until day 10 or 12. Warmer kitchens go faster.
When it's ready
You know your starter is ready to bake when all three are true:
- Doubles in size within 4–6 hours of feeding
- Passes the float test
- Smells pleasantly tangy — like yogurt, ripe fruit, or beer — not like acetone or nail polish remover
At that point, feed it one more time, wait for peak, and use it in a recipe. Any recipe on this site works.
Maintenance after it's established
The ratio never changes. Only the schedule does.
Counter starter (bake often) Feed once every 12–24 hours at room temperature, 1:1:1 with whole wheat flour. Best if you bake more than twice a week.
Fridge starter (bake occasionally) Feed once a week. Store in the fridge with the lid on (not airtight). To bake: 1. Take it out the night before 2. Feed it 1:1:1 with whole wheat flour and leave on the counter 3. Wait for it to peak (usually 8–12 hours) 4. Use in your recipe
The fridge path is what most home bakers do. It's forgiving and fits a normal schedule.
How much to keep Bigger starter = more discard, more flour used. Smaller starter = less waste but needs more careful timing. For most home bakers, keeping 20–50 g of starter and feeding it 1:1:1 is plenty. Scale up the night before a bake if a recipe needs a lot (e.g., a recipe calling for 100 g of active starter — feed a 40 g starter with 40 g flour + 40 g water and you'll have 120 g at peak, enough for the recipe and to keep going).
Troubleshooting
| What you see | What it means | What to do |
|---|---|---|
| Nothing happening on day 2 | Normal | Wait |
| Nothing happening on day 4 | Kitchen might be too cold | Move it somewhere warmer (top of fridge, near a warm appliance). Stay patient |
| Rises and falls fast on day 3, then goes quiet | The false start — bacteria, not yeast | Keep feeding on schedule. Real yeast is coming |
| Gray or clear liquid on top | "Hooch" — starter is hungry | Stir it back in and feed on schedule, or feed more often |
| Pink, orange, or fuzzy spots | Contamination — mold | Throw it out and start over. This is rare but not worth risking |
| Smells like acetone / nail polish | Under-fed but not spoiled | Feed twice a day for two days, it recovers |
| Been feeding 10 days, still won't float | Kitchen probably too cold, or water has too much chlorine | Try filtered water, warmer spot, keep the twice-a-day 1:1:1 schedule |
A note on flour
Organic whole wheat is what I feed with, and it's what I recommend. King Arthur Organic Unbleached Whole Wheat is consistent, unbromated, and widely available. Bob's Red Mill and Central Milling organic whole wheat also work well.
Avoid self-rising flour, cake flour, and anything with added leaveners or preservatives — those aren't useless here, they'll actively work against you.
If you switch flour brands later, the starter might sulk for a feed or two while it adjusts. That's normal. Keep feeding on schedule.
What to do with the discard
Every feed produces "discard" — the starter you scoop out before adding fresh flour and water. Don't throw it away automatically. It has flavor and can leaven certain recipes even when it's not active enough to raise a boule.
On this site, three recipes are built specifically for discard: Sourdough Pancakes, Sourdough Banana Bread, and Sourdough Pumpkin Bread. They use discard the way other recipes use eggs or milk — as an ingredient, not a leavener.
Once your starter is established and you're feeding it regularly, keep a small jar of discard in the fridge. Add to it whenever you feed. Bake from it whenever it fills up.
When you're ready to bake
Once your starter passes the float test, start with Classic Boule. It's the master dough for this site — every other recipe branches from it. Get comfortable with the boule, then explore. The starter you built will be with you for as long as you keep feeding it. Years, if you want.