How to make your own sourdough starter: the path to great bread

Have you ever wondered how to make your own sourdough starter?

Whether it conjures up a crusty, flavorful loaf of bread or a bubbling crock of flour/water starter, sourdough is a treasured part of many bakers’ kitchens.

But where does the path to sourdough bread begin? And how do you start?

Start in your own home kitchen. And begin by learning how to make your own sourdough starter.

First, a word of advice. Sourdough baking is as much art as science. This method for making sourdough starter isn’t an exact match for the one you read on another site, or in a cookbook, or in your great-grandma’s diary.

If you have a process you’ve successfully followed before, then hey, stick with it. Or try this one and compare. All good.

A sourdough starter includes five key ingredients: flour, water, time, patience, and love. Click To Tweet

OK, ready? Let’s go.

The following timeline assumes you can find a relatively warm place (68°F to 70°F) to grow your starter. More on that below.

How to make your own sourdough starter via @kingarthurflour

How to make your own sourdough starter, day 1

Combine 4 ounces (1 cup) whole rye flour (pumpernickel) or whole wheat flour with 4 ounces (1/2 cup) non-chlorinated cool water in a non-reactive container. Glass, crockery, stainless steel, or food-grade plastic all work fine for this.

Note that whole grain flour (whole wheat or rye) is used at the beginning of the process. This is because whole grains contain more nutrients and sourdough-friendly microorganisms than all-purpose flour.

You also may have better results if you feed your starter with non-chlorinated cool water; from now on, we’ll refer to this simply as “water.”

Stir everything together thoroughly; make sure there’s no dry flour anywhere. Cover the container loosely and let the mixture sit at warm room temperature (about 70°F) for 24 hours.

A note about room temperature: the colder the environment, the more slowly your starter will grow. If the normal temperature in your home is below 68°F, we suggest finding a smaller, warmer spot to develop your starter.

For instance, try setting the starter near a baseboard heater, or atop your water heater, refrigerator, or another appliance that might generate ambient heat. Your oven, turned off but with the light on, is another option, as is setting the container of starter on a folded dish towel laid atop a heating pad on its lowest setting.

How to make your own sourdough starter via @kingarthurflour

A temperature-controlled bread proofer is the absolute ideal solution; if you bake lots of yeast bread, you might consider investing in one of these tools.

How to make your own sourdough starter via @kingarthurflour

Day 2

You may see no activity at all in the first 24 hours, or you may see a bit of growth or bubbling. Note that this starter looks fairly inert when viewed from up top.

How to make your own sourdough starter via @kingarthurflour

But when viewed from the side, you can see bubbles starting to form under the surface.

How to make your own sourdough starter via @kingarthurflour

Either way, discard half the starter (4 ounces), and add to the remainder 4 ounces (a scant 1 cup) King Arthur Unbleached All-Purpose Flour, and 4 ounces (1/2 cup) cool water (if your house is warm); or lukewarm water (if it’s cold).

How to make your own sourdough starter via @kingarthurflour

Mix well, cover, and let the mixture rest at room temperature for 24 hours.

Note: Why do you need to discard half the starter? It seems so wasteful…

Well, it’s necessary for three reasons. First, unless you discard, eventually you’ll end up with The Sourdough That Ate Milwaukee – too much starter. Second, keeping the starter volume the same helps balance the pH. And third, keeping the volume down offers the yeast more food to eat each time you feed it; it’s not fighting with quite so many other little yeast cells to get enough to eat.

Also, you don’t have to discard it if you don’t want to; you can give it to a friend, or use it to bake. There are quite a few recipes on our site using “discard” starter, including sourdough pizza crust, sourdough pretzels, and my all-time favorite waffles.

How to make your own sourdough starter via @kingarthurflour

Day 3

By the third day, you’ll likely see some activity – bubbling; a fresh, fruity aroma, and some evidence of expansion. The somewhat darker hue your starter got from its whole wheat beginnings will fade as you continue to feed it with all-purpose flour. It’s now time to begin two feedings daily, as evenly spaced as your schedule allows.

For each feeding, weigh out 4 ounces starter; this will be a generous 1/2 cup, once it’s thoroughly stirred down. Discard any remaining starter.

Add 4 ounces (a scant 1 cup) King Arthur Unbleached All-Purpose Flour, and 4 ounces (1/2 cup) water to the 4 ounces starter.

How to make your own sourdough starter via @kingarthurflour

Mix the starter, flour, and water, cover, and let the mixture rest at room temperature for approximately 12 hours before repeating.

How to make your own sourdough starter via @kingarthurflour

Here’s the starter after its 12-hour rest. It may actually appear to be bubbling less than it did initially; this is normal.

How to make your own sourdough starter via @kingarthurflour

Days 4, 5, 6…

Repeat two-a-day feedings on days 4, 5, and as many days as it takes for your starter to become very active — almost foamy. If your starter is in cool surroundings, you may find it takes up to 2 weeks (or perhaps even longer) to get going.

When it shows a markedly different type of bubbling, though, it’s just about ready to use.

How to make your own sourdough starter via @kingarthurflour

When you stir it down and feed it this time, make a note of how high it comes on the bowl or jar. You’ll know it’s ready to use in baking when it doubles in size in about 4 to 6 hours. You’ll see lots of bubbles; there may be some little “rivulets” on the surface, full of finer bubbles.

Also, the starter should have a tangy aroma – pleasingly acidic, but not overpowering.

How to make your own sourdough starter via @kingarthurflour

When it gets to this point — doubling in size in 4 to 6 hours — give it one last feeding. Discard all but 4 ounces (a generous 1/2 cup). Feed as usual. Let the starter rest at room temperature for 4 to 8 hours; it should be active, with bubbles breaking the surface.

Remove however much starter you need for your recipe (no more than 8 ounces, about 1 cup); and transfer the remaining 4 ounces of starter to its permanent home: a crock, jar, or whatever you’d like to store it in long-term. Feed this 4 ounces of starter with 4 ounces of flour and 4 ounces of water.

How to make your own sourdough starter via @kingarthurflour

Let it bubble and become active for several hours before covering it and placing it in the refrigerator.

But wait — what if things haven’t gone exactly according to schedule?

No worries. If, after a week, your starter isn’t ready, don’t lose heart; keep feeding it regularly, and it will gain strength — really!

Be patient. The conditions in your kitchen may be more or less conducive to building a starter, depending on room temperature, the season, humidity, or how much you’ve been baking.

Remember, the keys to developing a successful starter are using good (unbleached) flour; having a consistent feeding schedule, and ripening (growing) the starter in an environment that’s adequately warm (at least 68°F, and preferably in the 70s).

Grape sourdough starter via @kingarthurflour

When your starter is strong enough, it’s time to go ahead and make your favorite sourdough bread.

Good luck! And enjoy.

Want something printable to follow? See our recipe for Sourdough Starter.

Next: maintaining your starter.

PJ Hamel

PJ Hamel grew up in New England, graduated from Brown University, and was a Maine journalist before joining King Arthur Flour in 1990. PJ bakes and writes from her home on Cape Cod, where she enjoys beach-walking, her husband, two dogs, and really good food!


  1. Eric

    I may have overlooked it, but how much starter do I add to a bread recipe. Maybe 1 tbs per cup of flour that the recipe calls for?

    1. The Baker's Hotline

      Eric, that would depend on what bread recipe you’re following! If you’re new to sourdough, we recommend trying our Rustic Sourdough Bread recipe first, as it uses starter but still gets an additional kick from some commercial yeast. Once you’ve mastered that, you can give Naturally Leavened Sourdough Bread a try, which gets all of its rise from the starter. The amount of starter is listed in each recipe, so you shouldn’t be left guessing. Happy baking! Kat@KAF

    1. The Baker's Hotline

      Hi, Mick! Your starter should be okay if you started out with bread flour. We recommend using all-purpose flour for subsequent feedings though so you can maintain the proper consistency and hydration. Happy baking! Morgan@KAF

  2. Joan comeaux

    Is it possible to makes starter in he fridge? I had abou 8 ounces of yeast already mixed with water so I put it in fridge and a couple of Tabl of flour every day abou week now. It smells great so maybe i’ll Take it out and let I sit on counter6 or 8 hours a backward sourdough method. Maybe pancakes, bisquits or English muffins. I just didn’t want to grow it out sooo what d you 🤔….…

    1. Susan Reid

      No reason not to make your slurry the start of something sourdough, Joan. The key is to discard all but 2 ounces of your refrigerator stash (or just pour off 3/4 cup and use it to make pancakes, then feed the rest). Check out Barb’s genius post on maintaining a smaller sourdough starter- just feed the slurry you have left as she directs. Susan

  3. Tony

    I am on about week 3 of my starter and it has just done excellent. I took it out of the refrigerator today which is at 38 degrees, just to look it over and it is bubbling a bit, has some “pockets of air” in it and has a little more than a tangy aroma. It doesn’t seem to be molding or souring but a bit stronger now than the previous weeks.

    Is this normal? Is it going bad? Should I be concerned? Do I need to do anything else to it besides feed it weekly?

    Please let me know, Thank you…..

    1. The Baker's Hotline

      Hi there, Tony! It is totally normal for the aroma of your starter to change slightly after a week of being in the fridge. Your starter sounds like it is quite healthy! Other than weekly feedings when stored in the refrigerator, you won’t need to do anything else to maintain your sourdough starter. Happy baking! Morgan@KAF

    1. The Baker's Hotline

      As long as the flour is whole grain, you should have success using it to begin your starter. We recommend switching to feeding your starter with all-purpose flour for subsequent feedings so it has the right hydration and consistency. You can save the rest of the whole wheat bread flour to use when you make the sourdough bread (rather than feed your starter). Feel free to let us know how it goes. Happy baking! Kye@KAF

    1. The Baker's Hotline

      Hi Robert, this recipe for Feeding and Maintaining Your Sourdough Starter should help better clarify the process. We recommend removing all but 4 ounces of your starter and then adding in 4 ounces of flour and 4 ounces of water for each feeding. (You’ll have a total of about 12 ounces of starter.) These quantities aren’t written in stone; you can adjust them to better meet your baking needs. It is helpful, however, to use roughly equal quantities of starter, flour, and water. This will make your starter happy, healthy, and vigorous, which are all keys to making fantastic homemade bread. Happy baking! Kye@KAF

  4. Jenny M-W

    Hi! Just made my starter tonight. Weighed rye flour and filtered water out in grams. It looks like a paste. Is that an appropriate consistency or is it supposed to be more liquidy even in the beginning? Total newbie over here! So I just don’t know what to expect. I’m a little concerned because I’m at a higher elevation, 5,500 ft and it’s drier here, hope I don’t have an uphill battle. Not many warm spots in the house but I do have it in a cupboard over the fridge covered with plastic wrap. Is there anything I should be doing differently because of the high elevation? Thanks!

    1. The Baker's Hotline

      Your starter sounds normal, Jenny — rye flour absorbs a LOT of water. You should be OK keeping your starter as is, but will want to make adjustments to any bread recipes you bake following our High Altitude Baking Guide. If you have any questions, our free and friendly Baker’s Hotline is available at 855-371-BAKE (2253) or through chat and email on our website so always feel free to reach out. Annabelle@KAF

    1. The Baker's Hotline

      No problem, Stephanie! Sprouted Wheat Flour is interchangeable with whole wheat flour so you can do a 1:1 swap. Happy baking! Annabelle@KAF

  5. Martin Fisher

    Hi there,
    Thanks for this, I followed a slightly different method and am looking for a bit of advice. I’ll go try discarding more as this seems the main key difference.
    Anyway it doubled in size after the 2nd day and looked great then I am worried it got infected with other bacteria as the smell changed to a less pleasant one and it became very thin and started to split on the top after day 4.
    Does that sound normal? How do you know whether you are growing a bad bacteria or a good “friendly” one? Do you have to be really careful with cleanliness of tools and containers used for measuring ingredients, i.e. do I need to sterilise them?

    Thanks in advance for and for this great blog.

    1. The Baker's Hotline

      Good questions all around, Martin! What you describe does sound quite normal to us. The starter usually starts producing more liquidy byproduct during day 3 to 5, which thins the starter as a result. “Bad” bacteria are often multi-colored; look out for spots of orange, pink, purple, blue, green, etc. We include photos of what this looks like in our blog called Sourdough starting troubleshooting. We also recommend checking out our full Sourdough Baking Guide, which has lots of visual examples of what a healthy starter should look like, as well as tips to get you there. Happy baking! Kye@KAF

  6. Olivia

    Mine also started out as a doughball. I’m about to go into my third day and it has not thinned out at all, and it almost feels hard to the touch on top. I measured by weight, and I live in San Diego, where the weather has hovered around 72 for the last few days. Did I do something wrong…?

    1. The Baker's Hotline

      We’d love to hear more about the ingredients you’re using, Oliva, and where/how you’re keeping your starter. We encourage you to continue feeding your starter as described in these guidelines and to give our Baker’s Hotline a call (855-371-2253). We’ll be able to troubleshoot more effectively this way and get you and your starter on track to sourdough success! Kye@KAF

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