Is My Sourdough Starter Dead? A Guide On What To Look For

Is my sourdough starter dead?
Published on
24 June 2021
Gareth Busby
Gareth Busby

Do you know what I love about sourdough starters? It’s that they are so resilient. You can forget about them for a couple of days (even weeks sometimes) and they’ll still be there waiting for you when you get back. Yet sometimes it can seem that a starter has become inactive. So how can we tell if a sourdough starter is dead?

A sourdough starter is dead when it doesn’t respond to regular feedings. If this is the case, the starter needs regular refreshments to be brought back to life. You may also see mould or discolouration, if this happens it’s often best to throw it out and start again.

If you think you have a dead starter, let’s look into the details to see if it has died.

Tests to tell if your sourdough starter is dead

There are a few tests we can use to see if a starter is dead. Here’s how they work.

#1 Review activity after feeding

After you feed it, are there any signs of life? Any bubbles, gas or any rise? If not, it could just be too cold. Try placing it in a warmer area to help kick it into action. If there are no signs of fermentation activity, but the colour looks ok it is dead, or almost dead. This can be most likely fixed by regular feedings alongside keeping it warm.

#2 Take a smell

Smelling a starter gives one of the best indications of its health. A starter that’s ready to use will smell pleasant, slightly alcoholic, probably vinegary and definitely aromatic. The most important factor when smelling is that you don’t feel the need to gasp for air afterwards! Common smells of gone-off starters are strong cheese, vomit, paint stripper and smelly socks.

If this is the case then your starter is bad, but not completely dead. If your starter smells horrible it just means it’s breeding the wrong types of bacteria.

To fix a foul-smelling sourdough starter, keep feeding regularly and adjust the temperature of your starter so it’s between 25 and 34C. Give it a few days and you will see it recover.

#3 Look at the colour

Starters that develop unusual colours such as blue, pink, orange or yellow indicate a lot of nasty bacteria has become prevalent which is likely to be mould. This is a clear sign that your starter is dead. You should probably start again if this happens to your starter however, if you want to revive it, you most likely can.

Take a small amount of the best bits and refresh it with lots of fresh flour and water as shown in my how to revive a mouldy starter video. After a few days of regular refreshments, the good bacteria should fight off the bad and you’ll have a healthy starter again.

If you handle a mouldy starter be careful to wash your hands thoroughly and not touch your face!

#4 Has it been baked?

Heating a starter too hot is the only way you can permanently kill one – I did say they are resilient! Once the temperature of the starter passes 60C (140°F) the lactic acid bacteria and the wild yeasts become irreversibly inactive.

If you keep your starter in the oven, be careful! There have been many instances where other members of the household have turned the oven on without checking what’s inside!

If this happens and your starter dries out before you realise it, you will have to start again.

What can I do with a dead starter?

First off, are you sure it is completely dead? There is likely to be some signs of life meaning discarding most of the starter and stirring in fresh flour and water will bring it back to life. If your starter is completely dead as it got too hot or mouldy, you will have to throw it away and start a fresh one. 

That said, I’ve always been able to repair a mouldy or discoloured sourdough starter. I’ve only had to do this a handful of times, but it’s a 100% success rate so far!

See the guide: How to fix a mouldy starter

Can I take a break from my sourdough starter?

If you are sick of the daily feeds or aren’t going to be home for a while you can absolutely take a break from your starter. After a big feed, it’ll keep in the fridge for a couple of weeks, no problem. It’ll just need a couple of days of refreshments to get it active again before using it for rising bread.

If you wish to store it for longer than a few weeks, you should consider storing it in the freezer or drying it out. View my guide on how to store a sourdough starter.

What won’t kill my starter?

There are a few common myths associated with killing a sourdough starter. Here are a few that are often mentioned:

  • Changing to wholemeal flour (or any other flour) will not kill your starter, it will just take a few days to adjust
  • Non-organic flour won’t kill your starter
  • Stirring with a metal spoon or placing it in a metal bowl will not kill your starter
  • Freezing won’t kill your starter

What if my sourdough starter never rises?

If you have followed a reliable sourdough starter recipe and are still not seeing bubbles or any other sign of activity, the problem might be the water. 

Will tap water kill my starter?

Water is a key ingredient in a sourdough starter. Tap water is fine to use, providing it’s suitable for drinking. In some areas though, tap water is heavily chlorinated. This removes the bad bacteria, but also the good ones. Pouring some water into a jug and leaving it to sit for a while will allow the chlorine to evaporate. After this, it can be used in the starter, even though there are few microorganisms.

A lack of microorganisms means the water’s activity is lower. The result is a starter that takes a while to rise. If you are still struggling with activity in your starter, try using bottled water instead.

Ending thoughts

I hope you now realise the difference between a dead sourdough starter and one that’s just in need of attention. If you have any further questions, view my how to bring a sourdough starter to life post, or drop a message in the comments below.

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Comments (18)

  • I had a robust starter. I left it in the fridge … last fed Jan 2021. 2 weeks ago (July) I pulled it out.. it looked blue and no appearance of yeast activity. 2 days of feeding brought it back to an even more robust product!

  • My starter is over a year old. I leave it in the fridge most of the time and once every week (sometime once every two weeks) I feed it. Same amount every time, (50g starter, 100 g of filtered water and 100 g of whole wheat flour)
    I have read it should double in 4 hrs.
    Mine usually takes about 10–12 hrs for it to double. Seems slow? Is something wrong?

    • Whole wheat flour will be a bit slower to rise, it could also be a little cold as it comes out the fridge. If it makes great bread then it’s fine. If you’re worried, feed it twice a day for 3-4 days to build up activity.

  • I left my starter in fridge for a month. Took it out looks like a white, on top smells like old socks has it gone bad?

  • My sourdough is very new (started September 8 2021). After the first 7 days of regular feedings every 12 hours I was seeing it rise (more than doubling in size) and fall predictably. Now for the past week it is barely rising between feedings. It still gets some bubbles, so I don’t think it’s dead but I’m not sure. I can’t figure out what the issue is. Any suggestions?

    • Starters will slow down a little as they change from producing yeast to both yeasts and lactic bacteria. Though I would have thought your starter should have adjusted by now. If there are bubbles, it’s not dead, maybe a little sleepy. Has there been a change in temperature or the flour that you are using? This will slow it down. What does it smell like?

      I’d be tempted to include 10-20% rye flour if you are not already using it. What temperature is it being kept at?

  • My Kitchen is currently about 70 degrees F (it was maybe 78 degrees when I started the starter). I haven’t changed the flour I am using. The formula that I have been following for the starter is 50 grams starter, 50 grams rye, 50 grams white, and 100 grams water. Am I maybe using too much starter in my feedings? I am wondering if I should decrease the amount of starter to maybe 20 grams?

  • My very active starter got ignored at room temperature for about 5 days (this has happened before with no problem reviving it) But this time there was no hooch and an incredibly strong vinegar smell. I fed it as normal and 12 hours layer there was only 2 or 3 bubbles and no rise! I fed it again and 12 hours later there’s about 6 bubbles and a bit of rise. Do i keep going on the 12 hourly feeds? Or leave it to bubble and rise more?

    • Hi Liz, The perfect time to feed a starter is when it reaches its peak so try not to worry so much about timing it, feed it when it rises. To speed up its recovery, warm it up to 25-35C.

  • I love your site! I found it randomly after searching on something like “does sourdough really need to rise a second time.” My starter has been with me for a couple of years now. I did leave it in the fridge, untended, for 6 months once, and when I got back, it was a little grey on the top. But I just scraped off that grey stuff, and did some regular feedings and it bounced right back. But the stuff I froze at the same time never revived. I’m a little puzzled about that, particularly reading on your site that starter can be successfully frozen. Wasn’t successful for me. Anyway, that was in Boston, MA. Now it’s with me in Mexico City, having been snuck across the border in the trunk of my car. I’m still learning how to bake at high altitude (2,200M ASL here), but it’s coming along.

    Thanks for such a great site!

    Kim G
    Roma Sur, Mexico City

    • Thanks So Much, Kim! I’ve had good results with freezing, but I guess it depends on how long it is left, the power rating on your freezer, temperature settings… I advise that you do two of these methods, just in case one doesn’t work. I’m interested to learn more about high-altitude baking. What do you find is different? Are you using less yeast?

  • Hi Gareth,

    I’m not sure I’m learning anything about high-altitude baking, to be honest. When I got here, I bought some local yeast and made a loaf of what I considered to be very bland and uninteresting bread. I should note that I typically use the New York Times No Knead Bread recipe, e.g. 3 cups of flour, 1/4 tsp yeast, 1 1/2 cups water, and lots of time to let it do its thing. I bake it in a dutch oven at 450° F for a half hour with the top on, then a half hour with the top off, trying to shoot for 350°F. That has worked very well for me in Boston, but here, it didn’t. Later I found some of my typical yeast and repeated and it worked OK.

    The thing I notice most about high-altitude is that it’s very drying. I’m personally very dehydrated unless I really think about drinking enough water. Rain evaporates very quickly, and stuff dries out very fast. Also water boils here at 196°F vs 212° at sea level.

    Recently I’ve made some decent sourdough loaves. The one before was bad, but I think I just hadn’t kept my starter sufficiently peppy.

    I’m not sure that the altitude affects bread all that much. I think it’s more of an issue for pastry. But I have to say, I’m a very low-volume baker, at most 1 loaf a week, and I’m a little sloppy with regard to timing especially. Sometimes I’ll let dough proof for many hours, some times less.

    For my last 2 sourdough loaves, I actually kneaded the dough for about 10-15 minutes after I mixed it. Then I folded it an hour or two later, and then baked maybe four hours after that.

    I wish I could tell you something more. Hopefully that’s at least interesting.

    Cheers, and thanks for the note.

    Kim G
    Roma Sur, Mexico City

  • Hi. This is my first attempt at baking bread and I’m trying to make a sourdough starter. I’ve used ½ cup of spelt flour to 1/4 cup lukewarm water.
    I’m on day 5 and the recipe said at day 3 feed twice daily, 12hrs apart. I’m getting a rise but not many bubbles and the starter is very stringy. It smells a little like weak beer today but didn’t float when I tested it.
    Does all this sound about right and when might it be ready to bake with?

    • Hey Sheree, that sounds about right. I find 100% wholegrain starters take a little bit longer to activate. You’ll probably need to repeat the regular feeds for another week or two. A spelt starter won’t have many bubbles, the bubbles will be smaller and the starter will be fairly dense compared to a white, wheat starter. Keep going until the aroma becomes intense and it begins to double in size between feeds.

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