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If your sourdough starter isn’t bubbling and doubling or behaving like it should, you need to give it a boost and strengthen your sourdough starter! Sourdough starters can suffer through a fair bit of neglect, but sometimes it can be a bit of a struggle to get them back on track. I’m going to share my tried and tested methods to strengthen a sourdough starter. It’s not luck, it’s consistency and understanding what is making your starter weak in the first place.

These tips will work to strengthen your sourdough starter if:

  • your starter is constantly smelling like nail polish remover, even after a feed.
  • your starter has been a bit neglected (left in the fridge unfed a bit too long) or you’ve skipped a few too many feeds on the counter (this has likely caused your starter to become acidic);
  • you’ve been growing your sourdough starter for a few weeks, it’s just not doubling consistently and seems to be at a plateau.
  • your sourdough loaves are consistently coming out lacking oven spring, with a gummy interior and pale crust.

What Causes A Weak Sourdough Starter?

A weak sourdough starter can be caused by many factors, but in my experience in helping thousands of sourdough home bakers grow thriving colonies of yeast and bacteria, the most common causes of a weak sourdough starter is acidity. Acid build up is caused by consistent neglect (leaving your starter in the fridge unfed for over 2 months or on the counter for a few days). This neglect allows the lactic acid bacteria to produce too much acid which essentially hinders the yeast. Wild yeast survive and thrive in a slightly acidic environment (which is why they can tolerate living alongside lactic acid bacteria), but they struggle to reproduce in a highly acidic environment, which means if your starter becomes too acidic, it stops bubbling (since the bubbles are created by the yeast).

If your yeast aren’t happy, then your dough will not rise. It’s pretty simple. 

A strong starter should double, or even triple, consistently after being fed (happy yeast equals a happy starter). The timing of this will depend on the feeding ratio you use. A healthy starter  should smell pleasant and yeasty and be teaming with bubbles. It should produce a lofty loaf with an open crumb structure. You can read more about how a sourdough starter works or when is your starter is ready to bake with

Use A Scale!

Always use a digital kitchen scale to weigh your sourdough starter, flour and water in grams. Using a scale means that you are consistently feeding your sourdough starter the same weight each time and not guessing anything. Remember, a cup of flour and cup of water do not weigh the same, so following ratios like this are not helpful and will cause you problems as you try to create a healthy sourdough starter. I’m pretty passionate about using a scale and weighing sourdough ingredients! You can read more about the benefits of weighing sourdough ingredients if you’d like to understand this more.

Stir Your Starter

One of the easiest ways to encourage a strong, healthy sourdough starter is to stir your starter between feedings. Now you might think this is too simple, but hear me out! The yeast and bacteria in your sourdough starter can’t actually move, depsite the fact that they are actually alive. Stirring your sourdough starter consistently actually moves the yeast around, giving them access to more flour and water, which is what they use to produce carbon dioxide, the gas bubbles which make your starter (and dough) rise!

Kate’s STARTER Tip

While a sourdough starter does not require oxygen in order to work, a little oxygen when you first feed your starter is actually helpful for the yeast, so stirring your starter really well after feeding and again after a few hours is not going to do it any harm!

Feed Your Sourdough Starter Superfood

If you have created your sourdough starter from a white, processed flour, it will really benefit from having a boost of rye flour. Rye flour is like a superfood to your sourdough starter and it will help to strengthen it fairly fast by providing additional nutrients. In fact, rye flour starters perform notoriously well (in my experience it’s better to use half rye flour and half bread flour or all purpose flour, rather than 100% rye flour). Rye flour will also help to make your starter more sour, which can make your sourdough bread more sour tasting too.

To boost your sourdough starter with rye flour, substitute half your normal flour with rye flour at each feeding for a few days and you should see a noticeable difference in your starter’s activity level.

Freshly milled whole wheat flour is also very beneficial to your starter if you have access to it and can help to increase the wild yeast in your sourdough starter. You might also enjoy this guide to feeding your sourdough starters different flours.

Discard Before Every Feed

It’s as simple as it sounds. Before you feed your sourdough starter, you must discard some. The easiest way to do this is to feed your starter into a clean jar and then just toss what’s left in the old jar. Not discarding can lead to an acidic starter that is sluggish, smells bad and doesn’t rise like it should. Read more about why you must discard sourdough starter.

Rethink Your Feeding Ratio

If your starter continually produces hooch, it’s a sign that it’s hungry. It may mean that you need to increase the amount you’re feeding it, rather than the frequency you feed it. 

Try doubling the amounts of water and flour you are feeding your starter each time – so feeding at a 1:2:2 ratio. A 1:2:2 ratio can be better than a 1:1:1 ratio because it can help to rebalance your starter. If you’re worried about using more flour, just reduce the amount of starter, so instead of 50g of starter, use 25g of starter, then you’ll still feed it 50g of flour and 50g of water.

You might like this in depth guide to sourdough starter ratios.

Keep Your Starter At A Lower Hydration

If your sourdough starter seems to be a little thin, it can be hard to see if it’s actually bubbling as the bubbles will escape very quickly and you won’t get any big bubbles on the side of your jar. Thin, runny starters can also become acidic very easily.

In order to strengthen your sourdough starter try and give it flour only for one or two feeds. This will make the mixture stiffer and essentially lower the hydration of your starter. 

If your starter is quite runny, it should be easy to stir the extra flour into the mixture. If it seems a little stiff, it will loosen up as it eats and ferments the flour.

Once you’ve done one or two feeds of flour only, your starter should be thick enough and you can go back to normal feedings of flour and water. 

If you’re concerned that feeding your starter flour only will upset it’s ratio – don’t be. If you need your starter to be at 100% hydration for a recipe, you can easily get it back to 100% hydration at the next feed. Just put 25g in a clean jar and then feed 25g of flour and 25g of water – you’ll then have a 100% hydration starter.

Boost your sourdough starter by keeping it at a lower hydration - this photo shows a jar of sourdough starter being held in a hand. It has large, deep bubbles up against the glass of the jar.
A sourdough starter kept at a lower hydration will be quite thick and spongy. You’ll need to use a spoon to get it out of the jar as it won’t be “pourable”.

Keep Your Sourdough Starter Warm

Starter temperature is so important when when you first establish your sourdough starter, and also when trying to strengthen a weak sourdough starter. A sourdough starter that is being kept in cooler temperatures (below 70ºF/21ºC) will not colonise and thrive as well as a starter that is kept above 75ºF/24ºC). The trick with this is to keep your starter warm, but not let it get above 28ºC because this will encourage the acid build up that we are trying to avoid.

Totally Refresh Your Starter

If you are really seeing no consistent activity from your starter, you can give it a complete refresh. This will generally get your starter going again after a period of neglect or even overfeeding. This is especially helpful if you suspect your starter has an acid build up. 

  1. Put 5g of your starter into a clean jar (you can discard the rest).
  2. Feed this 5g of starter with 25g of flour and 25g of water and stir in really well (this is essentially a 1:5:5 feeding ratio). 
  3. Cover loosely and leave this to peak (at least double). If it doesn’t double, then continue to step 4 after 12 hours.
  4. Take 5g from your jar and put it into a clean jar. Add another 25g flour and 25g of water to this 5g of starter, stirring really well. Cover again and leave until it peaks. It should be really bubbly and smell pleasant now. 
  5. Once the starter in your jar is at peak, it should be back to normal and you can use it to bake or at least start feeding normally. I recommend feeding your refreshed starter at a 1:2:2 ratio from now on to stop it from becoming acidic. Remember to discard to ensure you’re not getting that acid build up occurring again. 

I hope these tips help you to strengthen your sourdough starter and ultimately help you to bake better sourdough bread! Just remember that generally, a weak sourdough starter is caused by too much acid building up in your jar, so taking steps to correct the balance in your starter jar will bring you rewards for many years to come.

Frequently Asked Questions

Can I add sugar to my sourdough starter?

You can but there really is no need to. Sugar will give the yeast more to feed off, however this will not necessarily strengthen your sourdough starter. I would keep the sugar to add to your loaves – unless you are trying to create a sweet sourdough starter.

Why is my sourdough starter bubbling but not rising?

In the first few weeks of creating a sourdough starter, it is possible that your starter will bubble, but not actually rise (as in double). This is fine in the early stages of sourdough starter establishment. It just means that the bacteria in your jar are fighting it out for supremacy. Once the good bacteria win the fight, you’ll see that your starter begins to double. It’s very normal for a sourdough starter to bubble, but not rise, for a number of days in the early stages. Just keep going.

Should I stir my sourdough starter?

Absolutely. As mentioned above, stirring is a fantastic way to get oxygen into your sourdough starter which is essential for its growth.

Should I add pineapple juice to my sourdough starter?

No! There is absolutely no need to add pineapple juice to your sourdough starter. This will change the acidity in the jar. Just stick to flour and water (along with the tips in the post above).

Can you feed a sourdough starter different flours?

Yes you can. It’s a good idea to add rye to give your starter a boost (if you think it needs it). If you are swapping flours (like swapping from all purpose to whole wheat or vice versa) understand that your sourdough starter may go through a little dormant period while it adjusts to the new food source. It will recover, but it might take a few days. Unless you are unhappy with your sourdough starter’s progress, it’s generally better to stick to the same flour for each feed to maintain a consistent starter.

Will the water I feed my sourdough starter make a difference?

Absolutely – the quality of the water you feed your sourdough starter is very important. You should avoid distilled, reverse osmosis and chlorinated water. Check out this guide to the right water for sourdough starter.

Share the sourdough love!

Hey There!

I'm Kate, The Pantry Mama.

I can help you find your sourdough rhythm and bake sourdough with confidence and intention - even if you’re busy! I share tried and tested sourdough recipes, as well as practical, easy to follow tips that you can action today, for better sourdough tomorrow! Join me, and let’s bake sourdough together among the chaos of everyday life!

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71 Comments

  1. Vesta Ramsey says:

    This has been such a help having this information. Thanks

    1. Carol sanders says:

      Thank you you have really helped me understand my starter

  2. Beatrice says:

    Hi. 🙂 I totally refreshed my starter as you described, but after the steps i’m left with a tiny amount of starter at the bottom of the jar… Should I feed it more for it to grow? It’s just runny soup and how to see that it is hungry if i can’t see rising/falling, since there is so little of it. Should I feed it every 6 or 12 hours? Or should i mix some whole wheat flour? I’m feeding with organic strong white bread flour. Desperate 🙁 maybe i killed it completely…

  3. Lindi says:

    I had Almost given up on making Sour Dough Brwad ever again. Of late its coming up on my feed again, I think the universe is saying give it another go, your tips are so easy to follow and understand, so maybe it is time to try again.
    When I didn’t manage to kill my starter my SDliaves always came out looking and tasting great, it was keeping the starters going, l can see by reading your tips some might have been okay…hahaha ☺👍💫

  4. Margaret says:

    After you feed starter do you leave out of fridge for some before you but back in fridge

  5. Christine says:

    Thank-you!!Huge help!

  6. Margaret Fortmann says:

    Thank you so much. This info is very helpful.

  7. HH D says:

    can i use whey as a booster?

  8. Cyndee Jean says:

    When my bread is rising, how do i keep it from drying out? Then it seems like it stops the bread from rising. Can i put an oil on it while its rising?

  9. Kenny says:

    My sourdough starter had fallen into the somewhat inactive, stored in the fridge, and not fed enough category. I’ve been doing hybrid yeast + sourdough starter for a bunch of years and want to try going back to pure sourdough starter. After reading your article, I have been doing some mad science the last few days in hopes of getting to the doubling you describe and can report success; albeit I haven’t baked with it yet. What I discovered is that if I feed it in the morning, and it will double within 4-6 hours, but if I leave it out, by dinner time it diminishes in volume significantly by dinner time. The first few days only gave it a modest increase, but I fed it twice one day and that made a difference (I ordered some rye flour and hope to try that too). Given what I’m describing, when I want to bake, do I need to feed it, and wait for it to double before using it, and adjust my baking schedule accordingly?

  10. Olivia Jordan says:

    I am trying to make sourdough with gluten free flour. My starter isn’t bubbling but is very fluffy. Any help would be appreciated!

  11. Karen says:

    Thank you for this very helpful explanation. ive been baking sourdough for over a year now and I had no idea about any of this.

  12. Anna says:

    Hi , thank you for the information. Went will I know my starter is ready for me to start baking with it

  13. Melanie says:

    Thank you so much for this info. I have a new starter going and this is so helpful.

  14. Patty Paulsen says:

    Trying to boost the activity of my starter…it was doubling, but not many bubbles in the starter. It NEVER achieved the float test. So I fed it, then stirred it an hour later. Set the timer and stirred it again, and then once more before I went to bed. OMG, you were right, oxygen is the key! That and I loosened the lid on my jar produced a starter that tripled and was riddled with bubbles. You. Are. A. Genius.

    1. Kathy Kendall says:

      I’m glad to see this comment about stirring. I just read Pantry Mama’s comment that starter needs oxygen. I’m going to try what you do and see what happens.
      Been cooking and baking for 65 years and even taught foods, but I have not, for the life of me, been able to master this bread. BUT I WILL!

  15. Betsy says:

    Thank you so much for sharing all this information!!!! It’s been THE Biggest help!!! My chickens are Nucking Futs over the starter discard!!! Thanks again!

    1. Sue says:

      😂😂😂
      Now i know what to do with discard starter.

  16. Mckay says:

    My starter always doubles after feeds before baking, but the second rise for a sandwich loaf takes incredibly long, any tips?

  17. Steve says:

    Awesome – I have been feeding my starter for weeks now and it was just not strong enough. After reading this page, I added 1 tbl spoon of Rye flour to my 200ml starter, no water, and within 6 hours I had a starter that doubled to 400ml. Thank you

  18. Jeff Glover says:

    I grew up in the San Francisco Bay Area, and love the sour taste of Fisherman’s sourdough bread. I can’t get that sour taste. What tips would you offer to try to get that great sour taste?

  19. Hemalatha says:

    Hello Bakers,
    Please educate me which sourdough starter tastes better, a slow or a fast fermented starter?

  20. Phyllis says:

    My starter is about 10 days old. It rises beautifully after feedings 9more than doubles) but I don’t see the bubbles like in so many pictures. When I stir it, it has a thick airy consistency. Is it maturing properly?

  21. Sue says:

    Can I use my starter straight from the fridge if it’s at a mature state?

  22. Sylvia Alt says:

    How do I clean my jars and spoons without clogging my kitchen sink?

  23. rachel says:

    I had hooch in my starter I fed it but did not discard 1/2. will it still work?

  24. Chelsey says:

    This is great information! I just have one question. I live in GA and every fall, gnats become a problem as the weather cools and they become desperate to come inside…and they LOVE my sourdough starter. (They once got in there and laid eggs…fortunately, I had shared some starter with a friend who was able to help me restart when I had to toss out the jar). I keep my starter in an airtight container for thus reason, which has previously not been an issue. But I wonder if you know of a better way to keep bugs out that will also allow my starter to get plenty of oxygen? I keep it out on the counter, but should I just start keeping it in the fridge?

  25. GJ says:

    I do so rarely (more like never!) leave comments but this article was so helpful. Was thinking of giving up on my starter yesterday. The article from another blog that I followed does not mention as much about the hooch… yours is perhaps less wordy but somehow more informative!
    Now I feel like keeping at it again… thanks for the tips. 🙂

  26. suzi says:

    read a lot of this, thank you but need some clarity. my starter is kept in the fridge in a closed plastic container. it’s almost 3 years old. i’d like to move it to florida with me. i’m not clear on the strengthening process before drying. I haven’t fed it in awhile but it performs beautifully when I bake.

  27. Joe says:

    My starter doubles fine I think, but I’d like to see it overflow like some of the bakers I follow.
    I have issues with the batards I bake. They don’t seem strong enough, and tend to droop once taken out of the banneton. I retard in fridge overnight for 12 hrs, and the poke test shows a slow spring back. I divide the batch and cook one in a Dutch oven which comes out nice while the batard comes out flat. I know there’s so many variables just wanted to see if u had any tips..thanks

  28. Janay says:

    hi, what is the reasoning for discarding half every time you feed it? That is something I have never done and my starter is still thriving and making great breads.

  29. Ann Farquharson says:

    Wow! Such clear, precise information! I have been making sourdough for about 3 years but I have learned so much from you. Thank you so much for this article. I will be following it from now on and actually sending it on to my son-in-law.

  30. Susan says:

    I have been making sourdough breads, tortillas, scones, English muffins and pizza dough for a few years now. My trick for getting a good rise on my sourdough bread is to place it in a cold oven and at about 450F and bake it until the internal temperature of the bread reaches 200F.
    I feed my culture right from being in the fridge and always have great results in my bakes. The culture doesn’t have to be bubbling like crazy and overflowing the container.
    That’s my experience!