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.
There are a few tests we can use to see if a starter is dead. Here’s how they work.
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.
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.
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!
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.
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
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.
There are a few common myths associated with killing a sourdough starter. Here are a few that are often mentioned:
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.
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.
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.
If you’ve enjoyed this article and wish to treat me to a coffee, you can by following the link below – Thanks x
Hi, I’m Gareth Busby, a baking coach, lecturer and bread fanatic. My goal is to help you become a better baker.
Suite 2646 Unit 3A,
34-35 Hatton Garden,