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. Brigitte Couture

    I am at day 3 and my starter smells quite a bit and not very pleasing aroma and it’s quite liquid compare to yesterday. We’re in Florida so high humidity and yesterday 77 in the house. Did it turn bad? Should I toss it? Will I poison everyone if I make the discarded starter waffle recipe tonight (made the sponge this morning)???

    1. The Baker's Hotline

      Brigitte, no need to panic! New starters take some time to settle down into a bacterial equilibrium, and funky smells are often a part of that process. People have described new starters that smell of everything from “nail polish remover” to “dirty socks”. (People who make fermented foods like sauerkraut know this phenomenon of an especially smelly start quite well!) You will not be poisoning anyone, especially since both the yeast and the bacteria are killed when you cook things at high temperatures. Keep going with regular feedings, and your starter will eventually settle into an aroma that you’ll recognize as tart and yeasty. You’ve got this! Kat@KAF

    2. Brigitte Couture

      I ran out of AP flour! Day 7 I fed it this morning and quite high in the jar so I think it might be ready, but can I feed it bread flour tonight and in the morning before putting it in the fridge? I have wheat, oat, sprouted wheat, barley flours but no AP 😉

    3. The Baker's Hotline

      No worries, Brigitte! Starter loves whole wheat flour, so go ahead and use that. You’ve got this! Kat@KAF

  2. Sharon

    Hello. Thanks so much for all the good information. I’m new to starters and am finding this very helpful. Before I found your website I had started a whole wheat sourdough starter using a recipe from another website and it only called for 1 tablespoon each of flour and water and it called for dumping all of it each day (but not cleaning out the jar) and then adding another tablespoon each of flour and water. I’m now on day 5 and, after looking at some bread recipes I realize I’m going to need much more than 1 tablespoon of starter. Can I just add 4 ounces of flour and water and keep going? I’d rather not start over.

    1. The Baker's Hotline

      You can definitely keep going with your starter, Sharon! While a standard starter is a fair bit larger than the one you’re maintaining, a tablespoon is actually the perfect amount for following our instructions for a smaller starter. When you want to use your starter to make bread, follow the instructions in Step 5 of that smaller starter recipe until you have enough starter to bake with, and an additional 20 grams (a heaping tablespoon) to keep behind to maintain and feed. For an example of how this can be done in around three feedings, check out our blog article Maintaining a smaller sourdough starter and jump to the section “Making bread with three feedings/builds.” Happy baking! Kat@KAF

  3. Howard

    We live in south east N.M. at 7500ft. . Low humidity and cool temps. Our home is usually cooler than 68F. I am constantly fighting to find the magic balance of liquid and dry goods. Can any one give some guidance as to where to start and what to look for when things are not quite right. Having lived in FL for the last 20 years at eight feet above sea level has spoiled me, this is a whole new world.

    1. The Baker's Hotline

      Hi there, Jeanette! When storing the starter in the fridge you’ll want to pull it out about once a week to do a maintenance feeding, as outlined in our Maintaining a sourdough starter blog article. You’ll follow the same steps for feeding it as you did while getting the starter established — keep a 1/2 cup (4 ounces), add a scant 1 cup (4 ounces) of All-Purpose Flour and 1/2 cup (4 ounces) of water, and mix until smooth. Happy baking! Morgan@KAF

  4. Emily

    This may be silly, but are you switching containers each time you discard + feed? Like measuring out 4oz into a new container and mixing into the new one ? If using a mason jar, is it better to cover with cheesecloth or a lid?

    1. The Baker's Hotline

      Hi Emily! You don’t have to switch the container every time, but if you’d like to you sure can. It can be helpful to have a container with clear, clean sides when looking for evidence of rising and falling. We recommend using the lid of the canning jar to cover the starter so that the top doesn’t dry out. Just be sure not to tighten the lid all the way so that the gases don’t build up inside the jar. Enjoy your sourdough journey and if you have any question feel free to reach out to our friendly bakers on the Baker’s Hotline at 855-371-BAKE (2253), we’re happy to help! Morgan@KAF

  5. Will

    Im about to start the 7 day process to make my starter using this recipe.

    I understand the process, etc. but should I require more starter for additional/larger recipes later on, is there a process/formula to yield more from the initial recipe without having to start the 7 day process all over again?

    Im hoping that once the starter has matured, it would be as simple as not discarding any starter during the feedings and adding equal parts of water/flour until I reach the desired amount.

    Is there a min ratio of starter to flour/water (during feeds).

    1. The Baker's Hotline

      Hi Will! To obtain a larger amount of active starter for a recipe you can weigh the amount of starter you have and then feed it equal amounts of flour and water. This should ensure that you have enough to use in your recipe but also some to continue on maintaining a starter. We do have a blog article on Maintaining a smaller starter that you might find helpful if you’d like to feed the starter less when you are just doing maintenance feedings. Happy baking! Morgan@KAF

  6. Anabel

    Im in d2 and my starter looks very dry not as wet as in ur photos. I started on d1 w/ 1cup flour and 1/2 luke water. However I got confuse when u said ‘4ounces flour (1 cup) & 4 ounces (1/2 cup) water’… what is ur 4ounces? 1 cup or 1/2cup? … or dis I miss something on d1?

    1. The Baker's Hotline

      Sorry about the confusion, Anabel, we can see how that sentence could feel all tangled up! This is taking into account that different ingredients have different weights. So half of your starter is four ounces, one scant cup of all-purpose flour is also four ounces, and half a cup of water is also four ounces. This is because water weighs quite a bit more than flour. So four ounces of water is a lesser volume, four ounces of flour is a greater volume, and four ounces of starter (which is a mixture of flour and water) is somewhere in between. Hope that’s helpful! Kat@KAF

    2. Anabel De La Garza

      Btw. Why the starting is with whole wheat flour and then feeding is all purpose flour? .. does whole wheat contains more yeast?

    3. The Baker's Hotline

      If you like, you can certainly keep feeding your starter whole wheat flour rather than switching over! It has more nutrients than white flour, which makes for happy yeast. When your starter is just a baby, this is really important. As you go on and are maintaining, it’s less critical. Starters that are fed rye flour can taste different from those fed on whole wheat, which in turn are a bit different from those fed on white flour. If you have the time, flour, and a sense of scientific curiosity, it can be fun to keep one of each and see which one results in your favorite loaf. Ultimately, most people eventually switch their starter over to all-purpose flour for a less esoteric reason: it’s less expensive. But feel free to experiment with other flours and decide what works for you. Happy baking! Kat@KAF

  7. John

    I’m only 12 hrs. in and wondering if I need to start over. We keep the house rather cool in the winter (65 degrees) so I put the starter in bottom over with the light on overnight. I got up and looked in on it and it’s looking pretty active already but I took the temperature in the oven and it’s 87 degrees. Too hot? Start over and find a cool spot?

    1. The Baker's Hotline

      John, 87° is a touch warmer than we recommend, but you shouldn’t need to start over. There are often places in a cooler house that are just a touch warmer, like on top of the refrigerator or in a dark-colored container on a sunny windowsill. Even storing your starter in the microwave (When it’s not in use! Don’t cook your starter!) can insulate it a little bit against the chill. Happy baking! Kat@KAF

    1. The Baker's Hotline

      Mick, it’s probably not too late! Take it out and feed it. (Whole wheat or rye flour is ideal for this.) It may take a few days to perk up, but unless it’s growing mold it will probably be fine. As Jeff Goldblum reminds us, life … finds a way. Happy baking! Kat@KAF

    1. The Baker's Hotline

      Sounds like you have a very happy and active starter, Michael! Keep feeding it on schedule. Unless your starter becomes sentient and develops a taste for human blood, there’s no need to worry. Happy baking! Kat@KAF

Post a comment

Your email address will not be published. Required fields are marked *