Here’s How to Tell When Is Sourdough Starter Ready for Baking

Updated: Feb. 25, 2021

You're not the only baker asking Alexa, "When is sourdough starter ready?" Here are three sourdough tests for you to try.

If you’ve noticed a certain sourdough obsession floating around the internet, you’re not alone. Homemade sourdough bread has become a quarantine baking staple for its rich flavor, crusty bite and deep satisfaction in conquering the Mt. Everest of bread baking.

Making sourdough bread is an involved process that can take up to two weeks to finish, and the magic ingredient is the sourdough starter. Knowing when a sourdough starter is ready is the trick to achieving a perfect loaf.

What Is a Sourdough Starter?

A sourdough starter is a collection of wild yeast and bacteria that give sourdough bread its savory flavor and light, airy texture. It’s made from flour and water and needs to be “fed” with more flour and water daily until ready for baking.

Here’s the secret to making a sourdough starter in a jiff.

How Do I Know When My Sourdough Starter Is Ready?

There are three things to do when determining if your sourdough starter is ready for baking:

Look for Bubbles

As your sourdough starter ripens, you’ll begin to notice more bubbles each day, as well as a strong sour smell. You may also see a clear liquid forming on the top. When you feed your starter, you’ll hear a crackly sound as the bubbles pop with mixing.

Check the Volume

An active sourdough starter can quickly double its volume. If you note that the volume has doubled four hours after feeding it, your starter should be ready for baking. To test this, place a piece of tape to mark your starter’s volume and then check back four hours after feeding it.

Will It Float?

Grab the kids for an impromptu science experiment when you test your sourdough starter in water. Place about a teaspoon of the starter into a cup of warm water. If it floats, it should be ready for baking. Even if your starter doesn’t float, it could still be ready; go by the volume test to be sure.

More Sourdough Questions?

Sourdough is different than other bakes, so it’s understandable if you have a lot of questions. Our Test Kitchen pros answer the most frequently asked sourdough questions. And if you find yourself with lots of extra starter on your hands, try some of these sourdough discard recipes.