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How to Make Sourdough Starter

May 11, 2024

A sourdough starter's purpose is to make your bread rise. Time encourages the growth of wild yeasts in a simple mixture of flour and water making a naturally-created leavener for bread baking.


glass jar filled with sourdough starter

How Many of Your Friends Are Making Sourdough Starter Right Now?

Come on in, the water's fine! And by “water” we mean bread-making. And by “come on in” we mean, learn how to make a sourdough starter with us! In the interest of full disclosure and credit-where-credit is due, when it comes to making sourdough starter, we're relative novices. Like so many others, when we embarked on this self-quarantine journey, we turned to home-y projects to comfort and occupy ourselves. Right away, making a sourdough starter seemed like the right project for this time. We knew we’d be at home, so keeping the starter fed wouldn’t be a problem. Plus, with so much uncertainty in the world, being as self-sufficient as possible just seemed like a good plan. And all it takes to make a sourdough starter is flour and water, so you likely don’t even need to make a trip to the grocery store to get one going! Like Merlin famously says in The Once and Future King, “The best thing for being sad is to learn something" and, so far, on our sourdough starter making journey, the work of learning to feed it, watching it grow and bubble has indeed been a balm for these strange times. So, enough talk. Want to learn how to make sourdough starter? Let’s learn something new together!

active sourdough starter in a glass jar

OK, Back Up. Exactly What Is A Sourdough Starter?

In short, a sourdough starter is a leavener, and its purpose is to make your bread rise. Fermentation over time encourages the cultivation of wild yeasts and good bacteria in a simple mixture of flour and water, and that process results in a sourdough starter—a naturally-created leavener for bread baking. When your sourdough starter is ready (we’ll explain how to tell when it’s ready soon) and it’s finally time to bake a loaf, you’ll use part of your starter instead of commercial yeast. A strong, healthy sourdough starter will ensure that your loaf of bread has plenty of rise and a tender, light, airy crumb.

food scale, whole wheat flour and water with a glass jar

What You’ll Need To Make Your Own Sourdough Starter from Scratch

It doesn’t take much to make your own sourdough starter. All you’ll need is:

  • Flour. This is a bit of a no-brainer, but it’s worth noting—because grocery stores are having trouble keeping flour on the shelves right now—that you’re going to need quite a lot of flour to cultivate a sourdough starter. You’ll be feeding your starter about a cup of flour a day for the first few days, and then you’ll increase to two feedings a day. So, you’ll ultimately need anywhere from 15 to 25 cups of flour to really get a starter going. We’re calling for regular old all-purpose flour, but you could use whole wheat flour instead, or even a combination of the two.
  • Water.
  • Some kind of container. Clear glass is ideal, so that you can see growth and monitor volume changes easily. A large mason jar is great, or a simple glass bowl works just fine.
  • Something to cover it with. A tea towel works great, or plastic wrap is fine, too.
  • A scale. ––not necessary, but sure is helpful.
flour and water mixed together in a glass jar to make sourdough starter

A Few Encouraging Thoughts, Before We Begin.

Before we jump into the sourdough starter recipe itself, let’s take a collective deep breath. There’s a lot of lore in the bread world—and let’s be honest, bread people are totally intimidating—and baking bread from scratch can seem like a skill that’s reserved for professional bakers only. Just forget about all of that. Bread is humble! It’s the staff of life! It’s an ancient food that humans all over the world, in all sorts of circumstances, have been baking for actual millenia. Still not convinced? We swear, you can definitely do this. Here’s why:

  • For the most part, sourdough starter is very forgiving. A lot of sourdough starter recipes say that you may notice bubbling after the first 24 hours, but that hasn’t been our experience. Two eager days into our first starter, we were seeing just about zero action. After a flurry of text messages to friends who are much better bakers than we are, we were comforted by a flood of responses along the lines of “my starter took almost a month to really get going” and “give it two weeks, at least”. In other words, just be patient, and stick with it.
  • Remember, sourdough starter is a leavener, and the first leavened breads ever made likely rose by accident. In his classic book On Food and Cooking, food scientist Harold McGee notes that “the earliest archeological evidence for leavened breads comes from Egyptian remains of around 4000 BCE. The first raised doughs arose spontaneously, since yeast spores are ubiquitous in the air.” In other words, sourdough starter wants to exist. We repeat: it grows by accident! With just a smidgen of intention, you surely can’t fail.
  • If you find yourself truly confused or deeply curious (or both), the King Arthur Flour website has a sourdough guide that’s an excellent resource. It has a lot of information about the science of sourdough starter—what’s going on between the wild yeasts and lactobacilli bacteria you’re cultivating in your starter that give it those exciting bubbles and such wonderful flavor.
flour and water in a glass jar to make a sourdough starter
glass jar filled with sourdough starter

Still Confused? Or Just Proud Of Yourself?

We hope we’ve talked you into giving this a go! If you try your hand at our sourdough starter recipe, let us know how it’s going! We’d love to know. If you run into questions, hit us up! Snap a photo of your sourdough starter as it bubbles away, and tag us on Instagram using @themodernproper and #themodernproper with your questions and comments. We love hearing from you!

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How to Make Sourdough Starter

  • Yields: 1 sourdough starter
  • Prep Time:  10 min
  • Cook Time:  0 min


  • 1 cup flour (whole wheat or all-purpose)
  • ½ cup cool (but not cold) water

To Feed the Starter

  • 1 cup flour (whole wheat or all-purpose), plus more as needed
  • ½ cup cool (but not cold) water


  1. In a 32-ounce glass jar, add 1 cup flour and ½ cup water. Stir together until a sticky paste forms and there is no longer any dry flour left. Scrape down the sides and cover the jar loosely with a tea towel or plastic wrap and set in a warm (aiming for about 70°F) place for 24 hours.

  2. After 24 hours, it's time to begin feeding the starter. If you don't see any bubbling yet, it’s ok. Transfer ½ cup of the starter to a medium bowl, discard the remaining starter left in the jar. Add a scant cup of flour and ½ cup water to the starter in the bowl and mix thoroughly. Transfer the mixture back to the jar. Cover the jar loosely, and set it in a warm spot for another 24 hours.

  3. After 24 hours, it's time to feed the starter again. By now (day 3) you should see some bubbling, and the starter will likely smell fruity and yeasty. Stir the starter, discard all but ½ cup. Feed the starter again with a scant cup of flour and ½ cup of water, stir vigorously to combine, cover and store for 12 hours.

  4. At this point, it's time to begin to feed the starter more frequently, about every 12 hours (or as close to that as you're reasonably able to do). Every 12 hours, scoop out a slightly-heaped ½ cup of starter and discard the rest. Then feed the starter with 1 scant cup of flour and ½ cup of cool water, stir and store. Repeat this process every 12 hours until your starter is ready. Your starter is ready when it is very, very bubbly, and doubles in size within 6-8 hours after a feeding. This can take anywhere from 7 days to two weeks.

Storing And Maintaining The Starter:

  1. Transfer a generous ½ cup of starter to its permanent home—we use a 32-ounce mason jar. Feed it with 1 scant cup of flour and ½ cup water, and let it rest at room temperature for several hours. If you're storing your starter in a jar with a screw-top, screw the top on very loosely to store.

  2. After a few hours, move the starter to the refrigerator, and feed it regularly, at least once a week. To use, bring the starter to room temperature and feed. Once it doubles in size, it's ready to use.

  3. If you decide to store it at room temperature, you'll need to feed your starter every day.

Note: Glass containers are best, stainless steel, or ceramic containers are also fine. If you are feeding your starter every day, it is best to rotate the jar one time a week. If you are keeping your starter in the refrigerator and only feeding it 1-2 times a week, then you can rotate the jar every 2-4 weeks.

Nutrition Info

  • Per Serving
  • Amount
  • Calories432
  • Protein14 g
  • Carbohydrates91 g
  • Total Fat2 g
  • Dietary Fiber8 g
  • Cholesterol0 mg
  • sodium7 mg
  • Total Sugars0 g

How to Make Sourdough Starter

Questions & Reviews

Join the discussion below.

  • Teresa

    Should you keep the starter you are discarding and just add to it to have several starters going at the same time? Or will this just become a monstrous project?
    Thank you! I'm eager to get started on my starter (no pun intended!).

    Feel free to keep it, but yes, your collection will basically just keep growing. You can also add it to pancakes! : )

  • Jennie

    I’ve heard I need to use better quality flour like King Arthur. Does it work with just regular Gold Medal brand?

    Yes! Any flour will work. Whole wheat flour "feeds" it more nutrients than regular all-purpose, so you'll likely see a bit more activity with whole wheat. But any brand should work!

  • Jenn

    Thanks for all these tips my sourdough came out pretty darn good for my first try, excited to try again!

    That's so great Jenn, great job!