Sourdough Starter From Scratch: Day by Day, in Grams
A sourdough starter is flour and water fed every day for about a week, until it doubles in 6 to 8 hours and smells tangy.
Last updated: October 20, 2026 · Originally published January 12, 2021
Food safety note. The FDA says flour is a raw food: “Never eat or taste raw flour, dough, or batter.” That includes your starter. Wash your hands and counters after handling it, and throw out any starter that shows orange or pink streaks.
Sourdough starter is the only pet that eats flour, never needs a vet, and still makes you feel guilty when you leave town. It is a jar of flour and water that wild yeast has moved into, and once it is going it raises bread with no packaged yeast at all. Keep it fed and one jar will last for years.
Sourdough Starter at a Glance
- Day 1: 50 g whole wheat or pumpernickel flour and 50 g cool water, covered loosely for 24 hours.
- Day 2: keep 50 g, feed it 50 g all-purpose flour and 50 g water.
- Day 3 on: the same feeding twice a day, about 12 hours apart.
- Temperature: 70°F to 78°F.
- Ready: doubles in about 6 to 8 hours, bubbly all the way through, with a pleasant tang. Usually by the end of day 5.
- Keeping it: in the refrigerator with weekly feedings.
Schedule and readiness signs from King Arthur Baking’s sourdough starter recipe.
What You Need for a Sourdough Starter
Not much, which is part of the appeal. Flour, water, a jar and a little patience.
- Flour to start: whole wheat or pumpernickel (pumpernickel is whole rye). Whole grain flour gives the wild yeast more to work with on day one.
- Flour to feed: unbleached all-purpose.
- Water: King Arthur’s rule is “If your house is warm, use cool water. If your house is cool, use lukewarm.”
- A container: glass, crockery, stainless steel or food-grade plastic, ½ to 1 quart. Glass lets you watch it rise. (Trust me, you will watch it rise.)
- A kitchen scale: optional, but it makes everything below easier.
Sourdough Starter Day by Day
This is King Arthur Baking’s schedule, in grams with the cup measures their recipe gives beside them. Every feeding is equal weights of flour and water.
| Day | What to do | Grams | Cups and spoons |
|---|---|---|---|
| 1 | Mix flour and water, cover loosely, rest 24 hours at about 70°F | 50 g whole wheat or pumpernickel + 50 g cool water | 7 tbsp whole wheat (or a generous ½ cup pumpernickel) + a scant ¼ cup water |
| 2 | Keep 50 g, discard the rest, feed, rest 24 hours | 50 g starter + 50 g all-purpose + 50 g water | about 6 tbsp all-purpose + a scant ¼ cup water |
| 3 | Start feeding twice a day, about 12 hours apart | Keep 50 g, add 50 g flour + 50 g water each time | about 6 tbsp flour + a scant ¼ cup water |
| 4 to 5 | Same twice-daily feeding. By the end of day 5 it should double in 6 to 8 hours | Same | Same |
| 6 to 7 | Not doubling yet? Keep feeding every 12 hours until it does | Same | Same |
Do not panic on day two. King Arthur says, “You may see no activity at all in the first 24 hours,” and that is normal.
Why Measure a Starter in Grams?
Because a cup of flour is not a cup of water. King Arthur’s ingredient weight chart puts a cup of all-purpose flour at 120 grams, a cup of whole wheat at 113 grams and a cup of pumpernickel at 106 grams, while a cup of water is 227 grams. So the old-school recipe of 1 cup of flour to ½ cup of water (the one this page used to give) works out to about 120 grams of flour and 113 grams of water. Close to equal weights, which is the same ratio as above. A scale just takes the guessing out of it.
Keep Your Starter Warm
King Arthur’s ideal range is 70°F to 78°F. If your house runs below 68°F, find a warmer spot: the top of the refrigerator or water heater, or a turned-off oven with the light on. Now, check on it, because an oven light can get a starter warmer than you think.
Is My Sourdough Starter Ready?
Here is what King Arthur looks for, and it matches what you will see on the counter:
- It at least doubles in volume in about 6 to 8 hours after a feeding.
- It is full of bubbles all the way through, with small rivulets of finer bubbles on top.
- It smells tangy, “pleasingly acidic, but not overpowering.”
- It does this reliably, feeding after feeding.
Once it passes all four, it is ready for bread. Our sourdough bread recipe picks up right there.
Feeding and Keeping a Sourdough Starter
You have two choices. Keep it on the counter and feed it every day, or keep it in the refrigerator, which King Arthur describes as “weekly feedings.” Unless you bake every day, the refrigerator wins.
So why throw any away? Because if you never discard, you end up with a bucket of starter, and the yeast has less food per bite. The discard does not have to go in the trash. Give it to a neighbor who wants to start baking, or use it in a discard recipe.
Before baking with a starter from the fridge, wake it up. King Arthur’s bakers say a thin layer of liquid on top means one or two feedings should do it, while a lot of dark liquid can take two or more days of twice-a-day feedings.
Hooch, Mold and a Starter That Will Not Rise
- Gray or black liquid on top (hooch). King Arthur calls it “merely alcohol and water” and “a visible cry for help: Your starter is hungry.” Stir it back in, or pour it off if there is more than about half an inch or it has gone very dark.
- Orange or pink streaks. King Arthur’s advice is “it’s best to throw it all out and start again.” Do that. This is not a fixable problem.
- No rise after a week. Check the temperature first (70°F to 78°F), make sure you are discarding down to 50 grams each time, and keep feeding every 12 hours. Some starters take longer than seven days.
Raw Flour and Starter Safety
It does not look like a raw food, but the FDA says, “Flour is a raw food. It may not look like a raw food, but it usually is.” Grain grown outdoors can pick up Salmonella and E. coli, and milling does not remove them. So do not taste the starter or the dough, wash your hands with soap after handling them, and wash bowls, spoons and counters in warm, soapy water. The FDA also says not to try to heat-treat flour at home. Baking is what makes it safe.
Naming Your Sourdough Starter
Basically, everybody names their starter. You are going to feed it twice a day and worry about it when you travel, so it might as well have a name. A few to get you going: Clint Yeastwood, Bread Pitt, Doughlly Parton and The Yeast of Burden. (Mine would be named after whoever forgot to feed it.)
Half of you are canning this fall.
Frequently Asked Questions
How long does it take to make a sourdough starter?
About 5 to 7 days. King Arthur expects a starter to double in 6 to 8 hours by the end of day 5, and says to keep feeding every 12 hours if it needs longer.
What flour is best for a sourdough starter?
Start with whole wheat or pumpernickel flour, then feed it unbleached all-purpose. That is King Arthur’s method, and whole grain flour gets the yeast going faster on day one.
How do you store a sourdough starter?
In the refrigerator, fed once a week. Give it a feeding or two at room temperature before you bake, and more if it has a lot of liquid on top.
What is the liquid on top of my sourdough starter?
It is hooch, alcohol and water made by hungry yeast. Stir it in or pour it off, then feed the starter. Orange or pink streaks are different: throw that starter out.
Can you taste sourdough starter?
No. The FDA says to never eat or taste raw flour, dough or batter, and a starter is raw flour and water.
Once your starter doubles on schedule, head to part two and bake the bread. A warm loaf with homemade butter and a bowl of bone broth soup is about as good as a winter supper gets.
Sources: King Arthur Baking, “Sourdough Starter”, “Ingredient Weight Chart” and “Black liquid on top of sourdough starter is totally fine”; U.S. Food and Drug Administration, “Handling Flour Safely: What You Need to Know”.
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| Food | Pressure | Pint |
|---|---|---|
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| Corn | 10 lb | 55m |
| Tomatoes | water bath | 35m |
USDA/NCHFP processing times & pressures for common foods.
View full chart →| Item | Store | Keeps |
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| Potatoes | cellar | 4–6 mo |
| Apples | cellar | 6 mo |
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| Well-done | 160°F+ |
Safe pull temps for steak & burgers, from Popular BBQ.
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1 cup rye 1/2 cup water…this doesn’t look right?????
I have starter here, on my countertop, that is documented back to the Alaskain gold rush of 1800s, sits on the counter, fed a tablespoon or so of flower every day, used as needed, can be dried and saved for just in case, excess starter is made into sourdough waffles, never tossed out., when making waffles, any left over waffles, are dried and given to the dog as treats. Your flour will set the flavor of your sourdough. Bread flour for bread and roles, all purpose, I use to feed starter, equal parts flour and decorated water. If you would like some of this wonderful starter I have, contact me.
I thought you had to feed it a half a cup of flour and half cup of water daily?
Nope, you can go longer between feedings once it’s established. You can also throw it in the fridge with a loose fitting cap (not air tight) for a week or more. Then pull it out and let stand at room temp before feeding again. It may take 1-2 feedings to wake it up. I have had mine for over 30 years through many moves, still makes fantastic bread.
as ya can see from photo this isn’t right. Send me some starter, please