Sourdough Starter

The simplest beginnings – flour and water – can lead to magic.

How to take care of your sourdough starter

Congratulations! You've just received a jar of King Arthur Flour's fresh sourdough starter. Your sourdough starter may look a little the worse for wear after its trip to your home. It may also have a sharp, astringent odor; this is normal. What it needs is food (King Arthur Unbleached All-Purpose Flour) and water.

Also, it's important that you:

  • Feed your starter within 24 hours of receiving it.
  • Don't consume the raw sourdough starter.
Your sourdough starter

Here's your container of starter.

Let's get started.

  1. Step 1

    Add ¼ cup lukewarm water to the starter in the container. Stir to dislodge the starter.

  2. Step 2

    Shake/stir to combine starter and water.

  3. Step 3

    Pour the starter into a large glass or ceramic bowl. Add 1 ¼ cups lukewarm water and 2 cups King Arthur Unbleached All- Purpose Flour (hereafter known simply as "flour").

  4. Step 4

    Mix until well combined. Don't worry about a few lumps; so long as there are no floury patches showing, you're good to go.

  5. Step 5

    Cover the bowl with plastic wrap, and let sit at room temperature (about 70°F) for 8 to 12 hours. After 8 to 12 hours, the starter will be bubbly.

  6. Step 6

    Stir the starter thoroughly, to deflate it.

  7. Step 7

    Pour off about half. You can share this extra starter with a friend, discard it, or use it to make waffles, biscuits, cake, or other tasty treats.

  8. Step 8

    Add ½ cup lukewarm water and 1 cup flour to the remainder of the starter in your bowl. Stir to combine. The starter will be fairly thick, like pancake batter.

  9. Step 9

    Cover the bowl, and let sit at room temperature for another 2 to 4 hours, till bubbly.

  10. Step 10

    Stir the starter thoroughly, to deflate it. Divide it in half; give half to a friend, discard it, or use it to bake something.

  11. Step 11

    Feed the remaining half with 1/2 cup lukewarm water and 1 cup flour. The batter will be thick. Lumps are OK; don't bother to stir them out.

  12. Step 12

    Cover the starter, and let it rest at room temperature for another 2 to 4 hours.

  13. Step 14

    After this resting/rising period, the starter will have expanded a bit and be bubbly — though not as bubbly as it might have been after its earlier rises.

  14. Step 15

    Stir the starter down. It'll be thick, light, and somewhat elastic.

  15. Step 16

    Your starter is now fully grown. Place it in a stoneware or glass container, loosely covered with a lid; or with a screw-on top, not fully screwed on. Refrigerate it until you're ready to use it in a recipe.


Like any living thing, sourdough can be unpredictable. Weather, the "microclimate" in your kitchen, the flour you use for feeding, and how and where you store your starter all influence its behavior.

Sourdough baking is one of the top subjects we address every day on our Baker's Hotline. We've rounded up the most common questions people ask, and have provided the answers in our sourdough FAQS.

For an immediate intervention—whether your bread is "rising sideways," you think you killed your starter, or you simply want some 1:1 help—contact us. We're available via phone, email, or live chat 7 days a week.