How To Know When Your Sourdough Starter Is Ready

Learn how to know when your sourdough starter is ready to bake delicious bread – signs, tips, and more for perfect results.

“How do I know when my sourdough starter is ready for baking?” is a question I hear A LOT!

In this post, I will walk you through some signs to look for if you’d like to determine whether you can bake bread with your new sourdough starter. But I will also give you some tips on how you can give your new starter a nice boost. Or what to do if you would like to bake bread with a young starter. 

If you don’t have your own starter yet, I encourage you to check out my step-by-step instructions on how to make a sourdough starter from scratch

sourdough starter flowing out of glass jar

This post contains affiliate links, which means I make a small commission at no extra cost to youYou can read my full disclosure.

#1 Look at your sourdough starter

If you are reading this, you have probably just made your own sourdough starter from scratch. The best way to determine the quality of your sourdough starter is just by looking at it. A mature starter should have these signs of readiness:

  • have visibly risen (some people like to put a rubber band around their jar to see how much it has risen)
  • have plenty of tiny bubbles
  • have a spongy texture

#2 Take a closer look

I prefer keeping my sourdough starter in a glass jar which allows me to see what’s going on inside. However, you can also take a small spoon or fork and inspect your sourdough starter.

It should look

  • spongy
  • have a web-like structure
  • have plenty of bubbles
sourdough starter in glass jar

#3 Did it get a good rise?

While I personally don’t think every successful sourdough starter needs to double in size, it should have visibly expanded after 4-8 hours. Of course, how much it rises depends a lot on the room temperature, humidity, and what kind of flour you have been using. At warmer temperatures, you will see more activity of the wild yeast while cooler temperatures may slow it down but favor acetic acid. I have written extensively about how to affect the sourness of your sourdough

#4 Smell your sourdough starter

After you have looked at your sourdough starter, you can also smell it. A ripe starter should have

  • a pleasantly sour smell 
  • tangy aroma
  • no unpleasant odor 

New To Sourdough? Check out My Super Simple Sourdough Course!

Preview of Super Simple Sourdough online course

#5 Taste your sourdough starter

I often like to put a small amount of sourdough starter on a spoon and taste it. It should

  • taste pleasantly sour
  • have a fizzy, effervescent quality
sourdough starter in jar with lots of bubbles

#6 Listen to it

Yes, I like to listen to my sourdough starter. If it’s a healthy starter, you should be able to hear some small popping sounds when you hold the top of the jar close to your ear.

The fermentation activity generates carbon dioxide. You can actually hear bubbles rise to the surface of your sourdough starter where they make little popping sounds. 

#7 Perform the float test

This is really simple: drop a small amount of starter in a small glass of water. The idea is that if it floats, you have an active starter and if it sinks, it’s not ready. 

I personally do not rely entirely on this float test. It is just one of the various signs and symptoms to determine if it’s ready for baking. In the event that your sourdough starter does not pass the float test, you can always use it just like sourdough discard in any of your sourdough recipes. 

drop of sourdough starter floating in a glass of water

What if you want to bake but your starter is still young?

Let’s say you have this great sourdough bread recipe and would love to bake but you are not if your starter is actually mature enough to bake with. In that case, I recommend adding a pinch of commercial yeast to your bread dough.  

Some sourdough purists may object and say then it’s not a true sourdough loaf. However, I don’t think there is anything wrong with helping your dough rise until you have an established starter. 

loaf of sourdough bread on kitchen towel

How to get a (more) active sourdough starter

Sometimes, you just need to give your starter enough time. 5-6 weeks is a good rule of thumb if you want to bake a loaf of bread. In the meantime, you can always treat it as discard sourdough starter.  Over time your starter will become stronger!

Here are some tips on how you can get a healthy sourdough starter:

  • keep it in a warm spot or use a proofing box (check out my review of the Sourhouse Goldie)
  • use warm water when you feed it
  • perform regular feedings
  • use whole-grain flours
  • for best results, use whole wheat flour although rye flour is the best flour
  • use a smaller sourdough starter and feed it with fresh flour
bags of four different types of flour on kitchen counter

More Sourdough Tips and Resources:

You might like to check out all my best articles on sourdough methods and how-tos.

Get the Sourhouse Goldie (a nifty warming device with my Friend discount for 10% off on your order)

17 Bread Baking Tools You Might Need

Watch my sourdough videos on my YouTube channel

How to Know When Your Sourdough Is Ready


  1. Need the corollary case, of the dormant starter. How to wake it up, and then the question here, know when it is ready to bake ?

  2. So confused the further we go down the sourdough starter rabbit hole. Haven’t baked a loaf yet but keep second guessing the viability of the starter, especially now after reading your 5 to 6 week estimate…. Several other estimates that vary from several days to 14 days plus. Realize that their are many factors but the more I read the more confusing it becomes.

    1. It really depends on who you ask. Many people will say to wait 5-6 weeks (also to make sure that the beneficial bacteria in the SD will outnumber any potential unwanted bacteria) but I have successfully baked with SD after 10 days ~ Anja

  3. You mentioned above to feed it but in your “How to make sourdough starter” page/video, you say yours doesn’t require feeding. So if I followed your recipe/video using buttermilk (yogurt) and flour, do I need to feed it? I’m on day 5 and it has a strong smell, I added a tad more flour as it was a little runny. Thanks

    1. I don’t feed it while making it. If it gets very runny, I might add a bit more flour. It sounds like you did the right thing ~ Anja

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