How to Make a Sourdough Starter

Making a sourdough starter is easy—all you need is flour and water for our recipe. Don’t worry—our pro tips and troubleshooting topics will help you from start to finish. Follow everything closely, and in days, you will have a fermented, active sourdough starter ready to use!

Already have an active starter? Jump right in and make a loaf of making sourdough bread with starter!

Maybe you’ve heard that making a sourdough starter from scratch is really hard. I used to believe that, too. In fact, when I was first starting out, I got my starter from a friend.

There was a sad ending when the oven was turned on, with a jar of sourdough starter inside. Learn from my mistake! After you make yours, read our article on how to store a sourdough starter so you always have a backup.

Sourdough starter is wild, natural yeast. It’s a simple combination of water and flour that slowly ferments in a warm spot over time.

This living, fermented culture needs nutrients and air to thrive. As a result, you will see bubbly activity occurring daily in your sourdough starter.

Ingredient Notes and Substitutions

You only need two ingredients to make a sourdough starter recipe – flour and water! However, the type of flour and water used are important.

Best Flour to Use

• We feed and maintain our starter with unbleached, all-purpose flour. For the best results, start with a fresh bag of high-quality flour like King Arthur and use the same brand and type for the first few weeks.
  
• If possible, start the starter with rye flour or whole wheat flour for the first day. Rye gives the starter a nutritional boost and makes it more active. If you don’t have it on hand, no worries, unbleached, all-purpose flour will work just fine.

When it comes to most sourdough recipes, use unbleached flour. The bleaching process strips the natural coating of wild yeast on the grain. A sourdough starter thrives on friendly bacteria in the wild yeast.

Using bleached flour won’t ruin your starter, but cause it to become less active over time. If you can’t find unbleached, you can use bread flour instead.

I cannot stress enough the importance of using the same brand of flour for the first few weeks of feedings. The protein percentages can vary from brand to brand, as can the type of wheat used. This can cause a reduction in growth and activity.

Changing brands can cause a decrease in activity. If this happens, it may take a few days of consistent feedings and discards in order to get your starter’s activity level up enough to bake bread.

What about organic flour?

Although some bakers don’t recommend organic flour for feeding newly established sourdough starters, we used organic all-purpose and rye flour in making one of our starters.

Use Filtered water

Water straight from the tap often contains chlorine. If filtered water isn’t an option, let the tap water sit out for 24 hours, so the chlorine can evaporate.

This sourdough starter recipe makes a 100 hydration-type starter, which means, it has equal amounts of water and flour by weight.

This is where a digital food scale comes in handy. If you use measuring cups, you’ll need twice as much flour as water, since water weighs more than flour.

The Best Environment for Sourdough Starter Fermentation

We’ve already covered the importance of using the right flour and water. The next one is keeping your new starter warm enough to encourage proper fermentation. Keep your sourdough starter in a warm environment as it ferments and grows. It needs a cozy place to ‘snuggle.’ Ideally, it should be in a location that is 75-85°F.

Over the past few years, we have helped troubleshoot many problems with sourdough. The most common issues and questions relate to trying to grow a sourdough starter in too cool an environment.

Storing and feeding sourdough starter in a cooler climate

Cooler indoor temperatures can make it difficult for starters to thrive. We found an inexpensive, handy solution! It’s a low-wattage heating wrap around the storage jar to keep it at the optimal temperature.

Wrap it around the top of the jar, for the ideal amount of indirect warmth.

Sourdough Starter Recipe

Day 1

Add the following to a 1-liter glass, ceramic, or stoneware jar or crock:

• 1 cup (120 grams) unbleached, all-purpose flour, rye flour, or whole wheat flour
• 1/2 cup (120 grams) filtered, warm water (85 to 90° F.)

Stir to combine. The mixture will be very thick and pasty. This is normal – do not thin it out! Your sourdough starter needs that flour for fermentation and energy. The mixture thins out 12-24 hours after each feeding.

Day 2

Look for signs of fermentation: tiny bubbles on the bottom of the starter, and pinprick-sized bubbles on top. If you don’t see any signs after 24 hours, ensure your starter is in an area between 75º and 80ºF.

How and When to Feed a Sourdough Starter 

Feeding and maintaining your starter is as simple as stirring in more flour and water, and discarding a little bit of the mixture along the way.

What is sourdough discard?

The discard is the portion you remove from a starter during feedings. Throw out the discard for the first 5 days. At this point, it isn’t fully grown and active.

For an established, active sourdough starter, the discard is the portion you will for the recipe you’re making.

Day 3

1. Remove 1/4 cup (60 grams) of starter and throw it away.
2. Add 1/4 cup (60 grams) of warm, filtered water. Stir to combine, then stir in 1/2 cup (60 grams) of unbleached, all-purpose flour.

Watch for signs of activity – larger bubbles and a hungry starter that is thinner than when you mixed it.

Day 4

Your starter might have a strong odor. This is completely normal.

1. Remove and discard 1/4 cup (60 grams) of sourdough starter, and stir in 1/4 cup (60 grams) of warm, filtered water.
2. Mix in 1/2 cup (60 grams) of unbleached, all-purpose flour.

Day 5

Once again, follow the steps and ingredient amounts from day 4 to feed the sourdough starter. Depending on altitude and temperature, your starter may be active.

If it doubles in size within 4-6 hours of feeding, you can use it if you want to!

We recommend making a low-rise recipe, like old-fashioned sourdough cake or tortillas. Wait until day 7 to make bread.

Feeding an Active Sourdough Starter

By the 6th day, your jar of sourdough starter should be very active and bubbly!

Day 6

1. Feed starter normally Once again, remove 1/4 cup (60 grams) of starter. Either discard it, or use it to make a sourdough discard recipe.
2. Stir in 1/4 cup (60 grams) of warm, filtered water, then mix in 1/2 cup (60 grams) of unbleached, all-purpose flour.

At this stage of the sourdough starter recipe, you may see the contents double in size 4-6 hours after feeding. After 12 hours, it will have a lot of bubbles and will look very much like a sea sponge.

Day 7

If the contents are doubled in size in 4-6 hours after feeding, you can use it! If not, keep feeding it for a few days, following the same schedule of daily feeding.

Knowing When Sourdough Starter is Ready to Use

Here are some signs that you have an active sourdough starter.

1. Your starter is at least 5 days old (for low rise recipes) or 7 days old (for bread).
   
2. Within 4-6 hours of a feeding, your starter consistently doubles in size.
   
3. Your starter looks spongy and full of bubbles all over.

What is the Float Test?

We do not recommend using a “float test” to see if your starter is ready to use. Some perfectly active starters (including the ones we make) never pass this test.

As you can see, though, ours makes amazing sourdough bread.

Care and Maintenance

A sourdough starter is a live culture that needs regular feeding to survive.

For weekly (or less frequent) use

Keep the starter in the refrigerator. Take it out 12 hours before you want to use it. Depending on how much starter you need for the recipe, discard (or save for later) half, then feed the remaining starter.

We recommend keeping a discard jar inside of your fridge. perfect for recipes that use a large amount of starter, like sourdough starter cinnamon rolls.

For daily use

If you will be using it every day, keep your sourdough starter on the counter and feed it once daily. 8-12 hours after feeding, it is active and ready to use.

How to bake with your sourdough starter

Feed it as usual 12 hours beforehand by removing 1/4 cup of starter (60 g). Add 1/4 cup of warm, filtered water (60g), then mix in 1/2 cup of unbleached, all-purpose flour (60 g).

How to increase the amount of sourdough starter

There will be times when you need a larger amount of starter for a baking recipe. In that case, you’ll need to know how to increase the sourdough starter. There are two ways to do this:

The best container for storing sourdough starter

To keep your starter healthy and active, using a proper container is important. A glass container is ideal. Don’t store your sourdough starter in plastic or metal containers.

After much trial and error over the past several years, we recommend using a Weck 1-liter tulip jar.

If you’re having sourdough starter problems, check our post for easy tips!

Recipe FAQs

Consider Making These Easy Sourdough Recipes…

If you tried this sourdough starter recipe or any other recipe on my website, please leave a 🌟 star rating and let me know how it went in the 📝 comments below. Thanks for visiting!