Skip to Content

When Does Sourdough Starter Mature?

Have you started your sourdough starter and have now started wondering how you will know when it is ready to use? You are not alone. Many people have found themselves asking the question: When does sourdough starter mature? And when can I start using it?

It will usually take between a week to two weeks for a sourdough starter to mature. You will know your sourdough starter has matured by its appearance; it should have doubled in size, look bubbly, and it should even have a slight layer of foam on the top.

Let us take a closer look at sourdough starters and when to use them to understand what signs to look for when it comes to your sourdough starter, when it is still processing and when it has matured.

How Do I Know If My Sourdough Starter Is Mature?

There are a few key signs that will let you know when your sourdough starter has matured and is ready to be used, and until you see these signs, try and avoid using your starter or messing around with it, as you do not want to disturb it unnecessarily.

Matured Sourdough Starter Look

The number one thing you want to be seeing in your mature sourdough starter is bubbles – lots of bubbles.

The more bubbles there are, the more activity is going on inside the starter; this is a good sign because you want lots of activity. If there is no activity, there is not any process taking place in your sourdough starter.

Bubbles in your sourdough starter result from the water and flour fermenting, which then releases carbon dioxide gas – the yeast and bacteria found in the starter will then begin to feed off the sugars and starch. 

This means that your starter is on its way to being good and nicely matured when you see lots of bubbles.

Another good sign that your sourdough starter is mature is its size. Your sourdough starter will continue to rise and repeatedly fall throughout the maturing process.

When your sourdough starter has reached its peak height (having doubled in size), this is a good time to use it.

An easy way to tell when it has reached this peak height is by doing the following: 

Once you had fed and given your sourdough starter a mix, put a rubber band around the jar to indicate where in the jar its height currently is.

You will then be able to clearly see when the starter has doubled, as it will have the same amount of starter risen above the rubber band as it does beneath the rubber band.

Matured Sourdough Starter Test

If you are really unsure whether your sourdough starter has matured yet, there is a test that you can do to check if it is ready. To do this test, you will need to do the following:

  1. Have a glass full of room temperature water ready.
  2. To ensure even distribution of the bubbles in your starter, give it a gentle mix.
  3. Use a teaspoon to collect some of the starter from the jar.
  4. Put the starter from the teaspoon in the room temperature water inside the glass.

If your starter floats, this is a great sign; this means that there are enough gas bubbles in your sourdough starter, and it is ready to be used.

If the blob of sourdough starter sinks to the bottom of the glass, it means that it is not ready – either it still needs to mature for a while, or it may have been left too long past its peak stage, and you will need to wait a while longer for the process to repeat.

What Happens If You Use Sourdough Starter Before It Has Matured?

A matured sourdough starter improves the taste and texture of your bread

When you bake with a sourdough starter that is not yet matured, two things will happen to your bread:

  1. It will not taste the same. Not allowing your starter to mature into the yummy, tangy dough that is used to give sourdough that distinct flavor will end in your bread just tasting like an average loaf of bread, and not sourdough.
  1. Your bread will not rise. If the yeast that is needed for your loaf of bread to rise has not been allowed the time to grow or activate, and the starter is used, there will be nothing to make your loaf of bread rise.

This will result in a disappointing, dense, flat loaf of bread that will not even taste like sourdough bread anyway.

NOTE: To discover how to influence the sourness of your bread, take a look at my article 18 Ways to Make Your Sourdough Bread More (or Less) Sour

This is why it is so important to make sure your sourdough starter is matured and ready (at its peak) to use when wanting to ensure a successfully baked loaf of sourdough bread.

Can You Leave Sourdough Starter To Keep Fermenting After It Is Matured?

If your sourdough starter has matured, but you are not ready to make the bread yet, you may be wondering if you can continue to leave it to ferment for a while longer.

Once your sourdough starter is matured and ready to be used, it should be used as quickly as possible and should not be allowed to continue fermenting.

If it is left to continue fermenting, it will most likely go bad and will not be good or safe, to be used.

After your sourdough starter is matured and ready to use, you can either continue to feed it and let the process repeat for a further 24 hours, leaving your starter in the fridge in-between feeds, or for a more long-term solution, you can freeze the starter.

Note: If you wonder how age affects the taste of your sourdough starter, check out my article Does Sourdough Starter Taste Better With Age?”

Freezing your sourdough starter is not a complicated process, and the starter can be kept in the freezer for up to a year before needing to be used. 

Before freezing your mature sourdough starter, do one more feeding where you will add double the amount of flour to the starter that you usually do to, resulting in a far thicker paste. 

Place the thickened starter into an airtight container and place it in the freezer until you are ready to use it again.

How Often Do You Feed Sourdough Starter Once It Is Mature?

Once your sourdough starter is mature, you will only need to feed it once more before using it in your baking.

You will only feed it one more time, as you do not need it to continue to grow or ferment because, as was discussed above, once it is ready, it should not be left for long, or it will very likely go off quickly.

So then, once your sourdough starter is mature and ready for use, you will need to feed it one more time, about 5 to 6 hours before you plan on using it.

Feeding your starter this last time is in order to get the starter to rise again and double in size and have a lot of bubbles in it to ensure the best result of your bread loaf you are using it in.

Once your sourdough starter is mature, roughly between 7 to 14 days after it was started, it will need to be used relatively quickly.

Don’t worry if you have a lot of sourdough discard in the beginning or are not able to use your starter as quickly as you should. Here are some ideas for what to do with your sourdough starter discard.


A matured sourdough starter is essential for flavor and rising in homemade bread

Sourdough starter will usually mature between one to two weeks (7 to 14 days) after the starter was started. 

Once the sourdough starter has matured, it is best that it is used as quickly as possible to avoid the starter being left too long and going bad.

To decipher whether or not your starter is ready to be used yet, check for the signs of a well-matured sourdough starter, and if you are new to the process and are not certain about if it is ready, but you suspect it may be, use the sourdough starter maturity test and see whether it floats or sinks.

Sourdough starters can be intimidating to work with if you have never done it before, so don’t worry about using this test the first few times until you can start to tell just by looking at your starter if it is ready or not.

You can start doing this test on your starter anytime after a week to two weeks when the sourdough starter would have usually matured at that point. 

Hi, I’m Aysha

I love spending time making the most helpful content I can so you can become a better sourdough baker.

If you’ve enjoyed what you’ve learned, consider saying “Thanks!” by leaving me a tip here. I appreciate your kindness and support 🙂