Sourdough starters are pretty tough and can withstand being neglected for a little while, but they can also go bad or die (become inactive) under the right condition and with enough time.
You can tell that a sourdough starter is bad or dead if it doesn’t respond to regular feedings after being unfed for a long time or if they develop any kind of mold or discoloration. The starter needs to be thrown out if you notice either of these signs.
Fortunately, your starter isn’t likely to go bad if you’re keeping good care of it. Feeding it regularly and making sure that you’re not contaminating it in any way will help towards preventing it from going bad or dying.
With that said, there are always signs that your sourdough starter might not be in the best condition, so it’s best to keep an eye on it to make sure that it’s not going bad.
Signs That Your Sourdough Starter Is Bad
When a sourdough starter has either died or gone bad, it’s about time you throw it out and start from scratch, unfortunately.
Although starters are quite resilient, they aren’t invulnerable and bad things can happen if you don’t take the best care of them.
If you’re unsure if your starter is dead/bad, there are some obvious signs that it’s time to get rid of it.
You know that your sourdough starter is bad after noticing the following:
No Activity After Feeding
A sourdough starter can last for quite a long time in the fridge, but it won’t last forever. Once it has been left unfed for long enough, it will have died.
To check if it’s dead, you should try feeding it once or twice a day for a few days and see how much activity you can get out of it. If it’s still alive and well, it will be doubling in size within a few days and almost as good as new.
If you’re feeding the starter and you’re seeing little to no activity whatsoever, there’s a good chance it’s dead and you’re going to have to start again.
A Foul Smell
It’s normal for sourdough starters to smell pretty funky. Some might smell like nail polish, mild vinegar, or even a little sweet. Most of the funky smells are from good bacteria, so you can feel confident that your starter is healthy.
You want to be careful if it gets smells that are very strong and foul. If your starter smells anything like strong cheese, vomit, or dirty socks, it has most likely gone bad and not safe to use.
When starters develop a smell this bad, it’s general because there’s a build-up of bad bacteria that’s overwhelmed the good bacteria. This leads to a terrible smell and it’s important to toss this away and start over.
Discoloration
If your sourdough starter develops any kind of funky colors, it’s a strong sign that the starter has gone very bad and absolutely shouldn’t be used.
If you have a healthy starter, there’s nothing that can cause it to change color.
Starters that develop colors such as pink, blue, orange, yellow, etc. all need to be thrown away as this indicates a lot of nasty bacteria being developed.
Visible Mold
I’m assuming that we all know that you shouldn’t be eating food with mold growth on it, so don’t do it if your starters have some either.
Some unlucky sourdough starters will develop mold spots under seemingly normal conditions, but there’s almost always something that’s contaminated it.
Some say that if there’s only a small amount of mold, it can be taken off the surface of the starter and it can be fed as normal. If the starter develops mold again within a week or two, it’s time to throw it out.
I personally believe that if it has any kind of mold, it means that there’s a lot of bad bacteria and it’s time for the whole starter to go in the bin straight away, unfortunately.
After Being Stored In High Heat
Okay, this technically isn’t a ‘sign’, but high enough heat is almost definitely going to ruin your starter.
If for whatever reason your sourdough starter has been exposed to high heat, it may be damaged beyond repair.
Temperatures beyond 120°F (around 49°C) are widely considered to be the point at which yeast and starters start to be damaged. Anything at this temperature or higher will leave you with an unusable starter.
Your starter might have been left in a hot car, hot room, or hot oven for too long and suffered from it.
You should try feeding your starter a few times to see if it still has any life in it before throwing it away.
What Can I Do With A Dead Starter?
Whether your sourdough starter is bad (mold, discoloration, etc) or completely dead, there’s no saving it, unfortunately.
Although you might have poured a lot of time into maintaining your starter, you can’t do anything to bring it back once it’s gone to far.
If your starter is bad or dead, it’s going to have the be thrown away completely. All you can do is build a new starter and do your best to keep it in the best condition possible so you don’t have to throw it away again.
A Tip For Keeping Your Starter Long-Term
The method I’m about to talk about can really save you if your sourdough starter happens to go bad and you need to throw it out. By doing this, you’ll be able to bring out a backup and have a healthy starter in a matter of days.
The method I’m talking about is storing some starter in dried or frozen form. When you’ve done this, all that needs to be done is rehydration or defrosting followed by a good feeding and you’re on your way to making sourdough bread again.
It’s great to have a backup starter whether you’re good at maintaining it or not. There’s always a chance that something can go bad and you’ll be left with no starter.
Here’s what you can do to store your starter properly
Drying Your Starter
Having a dried sourdough starter powder in your pantry is extremely convenient and easy to do. You can even mail your friends and family dried starter if you want!
This is how to easily dry your starter:
- Feed your starter and be prepared for when it is fully active.
- Take a large sheet of parchment paper and spread a generous amount of your starter onto it. Make sure to spread it very thin using something like a dough scraper or spatula. It helps if you’re using a starter on the thick side for this (100% hydration is good) so it doesn’t run off the paper.
- Let the starter sit for 24-48 hours in a dry area of your home (this can be done in an oven with just the light on if you’re in a humid area).
- Once completely dry, the starter will be brittle and can be crushed and stored in a jar as a powder or as flakes.
- When ready to use again, the dry starter can be rehydrated in a small amount of water before being fed gradually and built up to a healthy starter again within a few days.
This dry starter will last for a very long time in your pantry provided that it’s stored in a dry and airtight container. You need to keep moisture away from it or it could spoil.
Here’s a more detailed video on how to dry and rehydrate your sourdough starter by Full Proof Baking
Freezing Your Starter
Another easy, but less effective way to store your sourdough starter is to freeze it. This works, but the bacteria and yeast can die within a couple of months as the ice crystals form. The amount of time the starter can last in the freezer will vary, but it’s best used within a few weeks rather than a few months.
This is how to easily freeze your starter:
- When your starter is ready, feed it as you normally would.
- Take either a freezer-safe ziplock bag or icecube tray and pour the starter into it immediately after feeding.
- If frozen in an icecube tray, the starter should be put into an airtight container or bag as soon as it freezes in order to prevent too many ice crystals.
- The starter should be taken out to defrost in the refrigerator for additional feedings before being used.
The reason the starter is fed immediately before freezing is so it has nutrients to feed on whilst it’s defrosting.
Is A Starter Better Frozen or Dried?
When referring to which method is best for long term storage, it’s more effective to dry your sourdough starter.
This is best since it lasts for a very long time when dried and kept in the right conditions, so you can be sure that you have a strong backup in case anything happens to your ‘mother’ sourdough starter.
Drying your starter does require some more effort and you need to keep it in a dry environment, but it’s definitely worth it.
I’d recommend drying more of your starter every 3-6 months just in case anything happens to your backup.