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. Nicole

    Do I need to use unbleached all purpose flour or can I continue to use the same whole wheat flour I began with?
    If there is no activity within the first 24hrs must I still discard?

    1. The Baker's Hotline

      Nicole, feel free to keep using whole wheat flour! Yeast loves whole wheat and will happily feast on it for as long as you keep feeding it to them. We recommend discarding and feeding on a regular schedule right away. Even if you’re not seeing any activity yet, it doesn’t mean that none is taking place, just that it’s happening on a scale that’s not large enough to notice yet. Happy baking! Kat@KAF

  2. Camilla W von Bergen

    I am finally going for a gluten free starter. The initial mix, per the recipe, seems very clumpy. I am itching to smooth it out with a little more water. Bad idea?

    1. The Baker's Hotline

      Hi Camilla! It’s OK to add a little more water in, a teaspoon at a time. For future feedings just aim to stick with equal parts flour, water, and starter by weight. Annabelle@KAF

    1. The Baker's Hotline

      Hi Odile! We did an experiment with this last summer and found that the spelt starter was pretty inactive. It was alive and it smelled good after a few days but it didn’t seem to grow much until around day 10. If you were to start it with spelt and switched to all-purpose for feedings you may have more success but if you’re down for some experimentation, give it a go. Annabelle@KAF

  3. Kristy

    I started my sourdough started just 7 days ago, named yiesty boys, and everything was going great till today about 12 hours after I fed him he has just exploded out of my jar! I have been feeding once a day in the morning, today I took out 200g before adding in 150 ml of water and 150g of King Arthur flour. I guess where I am really confused is, why is he exploding out of my jar at a slow pace? Everything I read says you will know your starter is ready to use after it has risen 4-8 hours after feeding. Am I over reacting for my new starter?
    Thank you for your help!

    1. The Baker's Hotline

      Kristy, it sounds like you have a very active starter, which is something a lot of bakers dream of! You might find that feeding your starter smaller amounts twice a day will help keep things at a more manageable level. If the yeasty boys continue to escape, you might just need a larger container. Like any living thing, each starter has its own individual quirks, so it may just take a while to get to know what works best for your easily-excited friend. Happy baking! Kat@KAF

  4. Florida~Susan

    After all is said and done my starter has behaved(3rd attempt, first two from different sites ending in gloppy, ugly, no bubbles, no fruity aroma turned gray the other orange,just a mess.).But…this one is alive and well.I finally named her..Hazel..(didnt want to jinx it).My discard has already made wicked biscuts that get covered with home made strawberry jam.if i did this right, how much, by weight, starter should i have for my first sourdough bread loaf ?(pre-feed before making dough) I read i have to feed my starter on last time without discard before making so excited !

    1. The Baker's Hotline

      Susan, that’s a good question! You’ll want to look at the recipe you plan to make in advance. If you’re making our Naturally Leavened Sourdough Bread, for example, you’ll need 16 ounces (454 grams) of starter to bake with, on top of the usual amount of starter you’ll want to keep in your container (we like to keep 113 grams on hand, but feel free to follow whatever formula you’ve been using, since it’s working well for you). Working backwards, you can then calculate how many regular-sized feedings it will take to bulk your starter up to the necessary size, and plan to start early enough so that you can bake on the day you’ve planned for. Our Sourdough Baking Guide is a great resource if you ever get confused or stuck on this (it definitely feels complicated at first), or you can call our Baker’s Hotline at 855-371-BAKE (2253) for personalized help. But know that you and Hazel have got this! We believe in both of you. Kat@KAF

  5. Rachel

    Once the starter is ready to bake with, I am having a hard time understanding how to get the amount needed. Let’s say I need 3 cups starter (this may be way way out there).. And I am maintaining a 1 cup starter, disgarding half twice each day.

    How would I get it up to that 3 cups?

    1. The Baker's Hotline

      Rachel, you would keep feeding every 12 hours, but without discarding. You’d do this until you had enough for your recipe, plus enough leftover to maintain in your starter container. So you’ll need to do a bit of math and figure out when to stop discarding so that your starter will be bulked up and active when you’re ready to bake. We don’t think you’ll run into many opportunities to use three cups of starter for most home recipes, though, so it usually only takes a day or two to get enough. Happy baking! Kat@KAF

    1. The Baker's Hotline

      Hi Wendi! You can use discarded starter right away, and it’ll keep in the fridge for 2 or 3 days before it starts to get a little funky. Annabelle@KAF

  6. Rachel

    When you discard on day 2, if giving to a friend… Would they carry on with day 2 procedure as me or would that be THEIR day 1??

  7. Jess

    Is it possible to double the starter without killing it? I bake a lot with sourdough and use the discard. If i could double the starter i could be more efficient in my time in the kitchen.

    1. The Baker's Hotline

      Jess, you can certainly keep a larger starter! You’ll just want to make sure that you’re mixing it thoroughly when feeding it so that you don’t end up neglecting pockets, and also that you have a container large enough to keep things from overflowing even when your starter expands to 2 to 3 times its volume. Happy baking! Kat@KAF

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