Busby's Bakery School

My sourdough starter is not rising - help!

Despite best efforts, sometimes a sourdough starter will not rise and it frustrates many bakers into giving up sourdough baking. But, believe me there's a fix. I’ve had this problem, and many others have too, you are not alone!

If you can’t understand why the starter is not rising with those big bubbles you see on Instagram I hope after reading this we will resolve your sourdough starter issue.

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Why Does a Sourdough Starter Become Sluggish?

A sourdough starter is weak or sluggish due to the low amount of activity that it produces. Most bakers run into issues when making a new sourdough or when trying to revive an old one which has been left in the fridge for a while.

The ingredients in sourdough are water and flour. For these elements to develop the wild yeasts necessary for the worlds favourite levain we need to allow the bacteria in it to develop over time.

These bacteria increase their rate of production at warm temperatures with the peak being 35C (95F), If the temperature rises above 38C (100F) it starts to die down. 

To make sourdough we need four things:

  • Flour
  • Water
  • Time
  • Temperature

To understand why a starter is not rising properly we make changes to these four.

Should I start a new sourdough starter?

If you are having problems with your starter and think you need to start again I advise that you stick with the old one and follow these tips to get it active. Starting again will just lead to another failure.

You might as well adjust your technique on the existing one and get it firing as if there are no bubbles there will still be some dough maturation going on, which will be beneficial to the levain. 

If you have a really rancid smell coming from your sourdough then it’s time to consider starting again, especially if it is a rye sourdough.

The most common fix that I’ve used is to give a big feed. This forces the yeasts and enzymes in that exist to work harder and multiply to create an active starter.

How to boost your sluggish sourdough starter 

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The way I prefer to boost a struggling starter is to give it a big feed, it usually does the trick so I recommend that you start here:

Take 20 grams of your sluggish starter into a large bowl, add 150 grams of water and give it a mix. To this, you add 150 grams of flour and stir really well to remove any lumps. Leave for around 10 hours and you should have a much more violent starter. 

Repeat again if you need to.

Once it’s active you can revert to equal quantities of flour, water and starter for further refreshments, or whatever recipe you wish.

If this fails to work or you still want to get some extra juice from your starter here’s a few more things to consider.

How long do I have to wait for my sourdough starter to be ready?

If you are making a new starter and you don’t see bubbles after a few days it doesn’t mean to say that nothing is going to happen. A starter can be ready in 5 days, but many say they don’t get results until over a month.

The length of time that it takes for a starter to develop is depending on the flour, water and temperature used in its production. 

Will changing the water help my sourdough starter rise?

Sometimes the amount of chlorine in your tap water affects a sourdoughs ability to develop. I can’t say it has ever happened to me, but it can.

If you live in a soft water area there are fewer minerals in your tap water. This can affect your starter as fewer minerals present in the mixture slow down the rate can of fermentation, leading to a weaker stater and lower quality bread.

If you do think that water quality is the issue for sourdough starter is not rising try some bottled water and see if it makes a change.

Should I warm my starter up or use a proofer

Sourdough is quite happy operating at room temperatures of 15-35C (60-95F). Activity will be slower in cooler climates. if this is you it could be a good idea to warm it up.

Many home bakers keep their starter in the microwave or oven with the light on. A weak starter is not resilient to temperature changes so keeping it somewhere warm solely overnight can fix many starter issues.

If you have trouble keeping your starter warm I suggest you get a proofer. It will benefit your bread production as well. Here is the one that I recommend from Brod & Taylor:

(It's an afiliate link so Amazon sends me a small payment if you decide to buy one)

How selecting the right flour is important for sourdough starters

Flour with plenty of natural bacteria is going to provide the yeast and enzymes in the starter with plenty of food.

Selecting high-quality flour to make a sourdough starter will encourage a strong and vibrant levain.

1) Don’t change the flour in your starter

Good quality bread flour with a hint of rye is my preferred choice of flour for making sourdough. You should use the same flour every day to encourage the sourdough to develop the same bacteria and enzymes.

Changing the flour kinda rocks the boat a little, it should only be done if you want to change the sourdoughs profile permanently.

If you run out of flour then, by all means, use what you have, After a few successive feeds, the sourdough will adjust to the change.

2) Using rye flour to boost your starter

Trading 5-20% or white flour for rye rocket powers sourdough starters! 

The addition of more complex starches found in rye or whole grains controls the rate of fermentation. This happens as the starches are harder to break down. Additional flora found in wholewheat and rye grains also adds more bacteria to the starter, which it loves.

Adding rye flour adds a boast of controlled energy - It's been a gamechanger for many sourdough bakers!!

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In terms of flavour and rise there seem to be improvements, the inclusion of rye flour has always helped my starters.

As mentioned above, changing the flour in the starter is not recommended. Once your starter is becoming established and is rising in 12 hours or less start replacing a portion of the white flour with rye. After 3-4 days of regular feedings, the sourdough should be perfect to use.

3) Should I use organic flour for making sourdough?

Flour is filled with proteins, starches, fibre and bacterias. Organic flour is the same, but the difference with organic flour is that natural fertilisers and cleaning agents have to be used in its production.

I just watched a fantastic presentation by Dr Lyn at Bakerpedia. She states that the less violent cleaning materials used in organic flour production allow more of the bacteria to remain in the flour.

The extra bacteria (or flora) increases the activity of fermentation, creating a more active levain.

One extra point - Keep things clean!!

Adding additional bacteria from poor hygiene controls is not good for bread production. Yes, you may have heard otherwise as it will add bacteria to the starter but it is not the bacteria that you want. 

On its own, flour is capable of creating the bacteria for sourdough production. Having dirty hands or equipment will add unnecessary bacteria and unsettle the balance of the sourdough.
Baked sourdough bread

Sourdough starter is not rising - step by step guide to troubleshoot & fix

When troubleshooting a sourdough starter that is not rising we know that it is always going to be caused by the four things mentioned at the top of the article, flour, water, time or temperature. The tricky one is knowing which one to change. 

1) To start troubleshooting your starter start with temperature.

Daily feeds at normal room temperature are great for sourdough fermentation. Controlling temperature to a higher consistency than this will adapt the flavour and the speed that the bread takes to rise, but this isn’t important for simple homemade sourdough bread. If you are in a cold climate then try moving your starter to a warmer place.

2) Then time

Have you given it enough time? Sometimes it just takes longer to develop so repeat daily feeds for 14 days before moving on to the next step

3) Give your starter a boost

Follow the steps in the How to boost a sourdough starter section above.

4) Change the flour

If you are still not getting activity there must be issues with your flour or water. Try changing your flour to an organic bread flour with a pinch of rye, it will take a few days for your sourdough to adjust, but it will - don’t worry if it looks worse to start with!

5) Look at the water

The last thing to change is to change your water to bottled water and see if that makes a difference after a couple of days feeds.

6) Still no bubbles?

Go back through all the processes and check you are following them correctly, something must be wrong somewhere!! Reach out to me if you need more help.

Sourdough starter myths

There has not been much scientific testing into the production of sourdough which is why there are many varying ways to make sourdough bread. Bakery scientists simply don’t know all the answers! 

There are a few myths that many bakers come across to help their sourdough, I’ve posted a couple here with the science behind why they are myths instead of best practices so you know to ignore them. 

If you have any more that you would like clearing up feel free to send me an email and I’ll update it here.

Should I use ionized water to make sourdough?

Ionizing water removes minerals making the water more alkaline. Sourdough is acidic and should rate at around 4-5 on the ph scale. Adding more alkaline and removing the minerals in the water is the complete opposite of what a sourdough starter wants to achieve.

Using ionized water is not recommended for sourdough production.

Is distilled water better than tap water for sourdough starters?

As distilled water is slightly more acidic than tap water it is often considered to replace tap water when feeding sourdough starters. Distilled water is only 0.5 ph more acidic than tap water and a sourdough starter will drop to around 4.5ph when fully active so using slightly more acidic water will have very little benefit.

To create distilled water, minerals along with impurities are removed. Minerals are essential for sourdough bacterias to multiply, without minerals the starter will be weak and slow to rise. 

Distilled water should not be used in sourdough production.

My starter won’t pass the float test!!?

The float test does not work

The float test is not accurate or necessary which is why I don’t explain it on my website.


The best way to tell if a sourdough starter is strong enough to raise bread is to watch it after feeding. If it doubles (at least) in 6-10 hours, it is capable of raising the bread.


Further reading: My in-depth sourdough guide for beginners with a simple recipe

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