Despite best efforts, sometimes a sourdough starter just won't rise. It has frustrated many sourdough beginners to give up sourdough baking altogether. But, believe me I’ve had this problem and there's a fix. You are not alone!

If you can’t understand why the starter doesn't rise with those big bubbles that Instagram bakers seem to have on every pic, After reading you will resolve most common sourdough starter issues making yours look and be as powerful as the pros.

Sourdough bread selection for sale in an artisan bakery

Why is a sourdough starter sluggish?

A sourdough starter will be weak or sluggish because of the low levels of wild yeasts and lactic acid bacteria. It could be developing the wrong type of bacteria which create some unusual and largely unpleasant smells.

Most bakers run into issues when making a new sourdough or reviving an old one that's been left in the fridge for a while. To understand why there is little levain activity it's best to break things down and cover what makes a sourdough levain rise in the first place.

What makes sourdough active?

The ingredients in sourdough are water and flour. For the mixture to make bread rise it needs to develop lactic acids and wild yeasts. These elements are absorbed from the environment or produced as hydrated flour develops during the sourdough fermentation process.

For the starter to become fully active we need high levels of these two elements and providing we have these four things:

  • Flour
  • Water
  • Time
  • Temperature

We can produce an active levain. When one of these is low or missing we start to run into problems and the levain will not be as active as we need it to be.

When 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 with the same process usually leads to another failure.

You might as well adjust your technique on the existing one and get it firing. There will be some maturation in a less active starter which is beneficial.

Only if you have a really rancid smell coming from your sourdough is it time to start again, especially when you have a 100% rye sourdough.

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

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

To troubleshoot a sourdough starter which is not rising work through these stages. They focus on generating the best temperature, feeding levels, bacteria and time. Just start at number one and work through these tweaks to fix your starter.

1) Increase the feeds to boost the sourdough starter

The starter could be hungry so increase the size of the feeds and the frequency of them. This will provide plenty of bacteria for the the starter to ferment.

2) Increase the temperature

Daily feeds at room temperature are fine for sourdough fermentation but if you are in a cooler climate it could be too cold for your starter.

3) 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

4) Change the flour

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 your starter to develop the same bacteria and enzymes.

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.

6) Keep things clean

Sourdough is created through fermenting bacteria. Introducing and multiplying the wrong bacteria is not good for a healthy starter.

1) Give it a boost with a big feed

Gareth  weighing out starter for a recipe

I prefer to fix a struggling starter by giving it a big feed. This method usually shows an improvement in half a day. Just keep repeating until your starter is powerful enough to use.

Take 20 grams of your sluggish starter into a large bowl, add 150 grams of water and give it a mix. To this, 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 twice a day until the starter is active.

Once it’s potent enough you can go back to using equal quantities of flour, water and starter in further refreshments, or whatever ratio that works best for you.

If this method doesn't work or you think that it could be more vibrant there are few more tricks to consider.

2) Warm the starter

Sourdough works best in warmer temperatures. A fermentation temperature between 25-35C (77-95F) works best. To find out how temperature will affect the flavour of your starter view the sourdough starter troubleshooting post.

If the temperature falls outside of this range the rate of fermentation activity will reduce. If you live in a cooler climate it could be a good idea to warm it up. A weak starter is not resilient to temperature changes so keeping it somewhere warm solely overnight can fix many starter issues.

I offer some top tips on warming a sourdough starter on that post.

If you have trouble with warming your starter I recommend you get a proofer. It will benefit the production of your bread as well.

Here is one that's available in Europe from Brod & Taylor:

It's an affiliate link so I receive a payment from amazon if you decide to buy one. - Thank you!

3) Give it more time

Sometimes you just need to give your starter a little more time. This is common when its a bit cool for it.

How long does it take for a new sourdough starter?

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 bakers get better results after waiting three weeks to a month.

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

For a recipe and feeding schedule see the how to make a sourdough starter page

4) Change the flour

Flour with plenty of natural bacteria and minerals 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.

Here's a few top tips for selecting the right flour to make a sourdough starter.

Use bread flour

High gluten flour contains more ash and therefore more minerals. These minerals provide more bacteria and slow down the rate of fermentation which actually increases the leavening properties of the starter.

The higher amounts of gluten will take longer to break down during hydrolysis which when added to a dough it will help mature the flour.

Use rye flour to refresh the 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. Similar to using high gluten flour the additional flora found in wholewheat and rye grains adds more bacteria to the starter.

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

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

Switch to organic flour

Flour is filled with proteins, starches, fibre and bacteria. Organic flour contains the same amount than non organic. The difference with organic flour is that during the milling, weaker cleaning agents are used.

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.

Why changing the flour makes an impact

Changing the flour between brands and even packets rocks the boat a little, it should only be done if you want to change the sourdoughs profile permanently.

The organic ecosystem

A sourdough builds up an ecosystem of breaking down the same complex sugars and bacteria after every feed. It is a fantastic how a starter will generate enzymes and organic acids to maintain consistent levels of activity.

Offer a starter the same flour, water, temperature and time between feeds and it will train itself to contain the same profile forever.

The impact of changing the flour

Adding a different flour changes the sugars and bacteria which upsets the balance in the starter. It'll take a couple more feeds for the necessary enzymes to develop so they can break down and ferment the new flour efficiently.

In the mean time the activity of the sourdough will lower until the ecosystem is balanced itself again. 

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.

A sourdough levain

5) Change the water

Many ask if changing the water will help a sourdough starter rise. It's derived by artisan bakers using bottled water in their youtube recipes. Using bottled water "looks artisan" but it's impact is usually for looks only. There is rarely a need to change water to make decent bread. Though there are a few cases where you might want to test bottled water:

Chlorine

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

Soft water

Soft water has fewer minerals which will increase the rate of fermentation. This weakens the stater. If you do think the quality of your tap water is the cause of your sourdough starter not rising try some bottled water and see if it makes a change.

6) Keep things clean!!

Adding additional bacteria from poor hygiene controls is not good for bread production. Yes, you may have heard otherwise seriously, this is not the bacteria you want!

On its own, flour is capable of creating plenty of the bacteria for the production of sourdough. Dirty hands or equipment adds unnecessary bacteria which unsettles the balance of the sourdough.
Baked sourdough bread

Sourdough starter myths answered

There has not been too 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! 

But there are a few myths that I can discredit. These are told by many bakers across the world.

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 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 has very little benefit.

To create distilled water, minerals along with impurities are removed. Minerals are essential for sourdough bacteria to multiply. Without minerals the starter is going to 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: sourdough bread recipe for beginners

One Comment

  1. This is so helpful! I am in keto and trying to do a Lupin flour starter without success. There is only one on YT and I just can’t get her recipe to work. Going to try your tips. Thanks!

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