How To Revive A Neglected Sourdough Starter

Have you ever forgotten about your sourdough starter in the fridge for a week? 

A month? Three months?! 

If you don’t actually use your starter very often, or you took an extended vacation, it can be easy to lose track of your feeding schedule. Or worse yet, forget about your starter altogether.

While many of us obsess over and baby our living starters, they’re actually quite resilient and can handle a lot of neglect. At least as long as that neglect takes place under refrigeration.

So, even if you’ve left your starter unattended for months, and it’s developed a terrifying black liquid on top, all is not lost (hopefully). 

In this article, I’ll go over how to tell if your starter is dead or just really hungry. Then, I’ll explain the simple steps you can take to nurse it back to health. So, read on before pulling the plug on your precious sourdough starter.

Is Your Starter Revivable?

how to store sourdough starter

Before you even begin the steps to revive your sourdough starter, you need to determine if it’s salvageable or if it’s beyond saving.

If you forgot to put your starter in the fridge and went on vacation for a week, you’re more than likely out of luck. A starter that has been left unfed, at room temperature for more than a couple of days is unlikely to survive.

But, a sourdough starter stored in the refrigerator can often last for months, even without being fed.

So, before sending your old starter to the trashcan graveyard, follow these two steps to determine if it has any life left.


First, take a close look at the starter in question.

You’re looking for two things. Visible mold, and any pink, red, or orange tint in the starter itself or the liquid that may have formed on top.

In most cases, any liquid that forms on top is fine. This is called “hooch”, which we’ll get into in a moment. The liquid can be clear to almost completely black, no problem. But, if you see a reddish tint, that’s the end of the road for that starter.

If there’s any mold on the surface or even just on the sides of the container, it’s a sign that your “good” yeast and lactobacilli have been overrun by “bad” bacteria. 

Again, that means it’s time to say your goodbyes.


Your next test for starter viability is to give it a good whiff.

Normally, a healthy and regularly fed sourdough starter will smell yeasty, sweet, tangy, and generally pleasant.

When left unattended for a long period of time, you can usually take pleasant off the list. But that doesn’t necessarily mean the starter has gone bad. You might get an aggressively sour, vinegary, or even a smell akin to nail polish remover, but that’s ok.

This is just a result of the yeast and “good” bacteria continuing to ferment and produce alcohol. A good sign that they are still alive.

It’s only when you get dull, musty, and moldy smells that you’ll want to go ahead and toss your starter and begin again. 

What’s That Dark Liquid On Top Of My Starter?

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If you store your sourdough starter in the fridge, there’s a good chance you’ve come across a layer of liquid that’s formed across the top of the starter. This is often referred to as “hooch”.

Sourdough starter is a fermented culture. Meaning yeast and bacteria are at work converting sugars and starches into gas that helps bread rise, and lactic acid that puts the “sour” in sourdough.

But, when the yeast and bacteria start running out of food, the fermentation process continues, and sugars are then converted into alcohol, a.k.a. “hooch”.  

And while it doesn’t exactly look appealing, it’s really just a sign that your starter is hungry, and in most cases, it’s nothing to worry about.

When you go to feed your starter again, you can pour off the hooch if it gives you the heebie-jeebies, or you can simply stir it back in. In fact, mixing the hooch back in is often preferable as it helps maintain the proper level of hydration in your starter.    

How To Revive Sourdough Starter

Now that your sourdough starter has passed the look and smell test, it’s time to get it fed and back in action.

Warm It Up

starter in a jar

If your starter is coming out of the fridge, go ahead and allow it to sit at room temperature for an hour or two. This will give the bacteria time to warm up, wake up, and get ready to eat the feast of flour you’re about to feed them.

Feed It

flour and scale

Next, grab a clean jar, a digital scale, flour (use the flour you normally feed your starter), and water. 

In the clean jar combine 50g starter, 50g warm water, and 50g flour. Mix well.

If you normally use a different feeding ratio feel free to use that here. Using equal parts is simply easy to remember and easy to scale when you want more or less starter for your baking projects down the road.

Cover and Rest

Loosely cover the jar and let it sit at room temperature for about 12 hours. After this first feeding, you may not see as much activity as you are used to during your normal feedings. But, things should start to pick up in the next feeding or two.

Feed Again

After the first 12 hours, repeat the same feeding again. 50g starter, 50g warm water, 50g flour (or your normal feeding ratio). 

After this feeding, you should get a bit more activity. It might still be less than normal, but a few bubbles here and there are just fine. 

What you’re looking for is for your starter to at least double in volume within 12 hours of feeding. This could happen after the first or second feeding, but it can also take a few more.


how i feed my starter

Continue to feed your starter every 12 hours for 2-3 days. If it is at least doubling in volume after each feeding, it should be ready to bake with.

At this point, you can switch back to one feeding every 24 hours if you’d like. Or, you can go ahead and store the starter back in the fridge and feed it once a week.

Things To Make The Process Easier

When it comes to feeding, maintaining, and reviving a sourdough starter, these few things will make the process easy and successful.

First, a set of jars that are dedicated to your starter. Any jar will work, but having two glass jars that are only used and always available for your starter is incredibly useful. You’ll never have to rummage through your cupboards or empty out a container full of leftovers because you don’t have a clean jar for feeding.

Second, a digital scale. This is essential for maintaining and reviving your sourdough starter. Being able to easily measure your starter, flour, and water, down to the gram will ensure more consistent results. Not to mention it’s the best way to measure ingredients for most baking projects.

And last, a steady, warm environment. This one’s not always quite as easy to control, but the yeast and bacteria in your starter thrive in temperatures close to 80 F. A warm environment is especially useful when trying to bring back a starter that was on the brink. 

If your house runs cold, try placing your recovering starter on top of your fridge, or in the oven with the inner light turned on. And if you want even more control, check out a countertop convection ovens with a built-in, low-temp proof setting.

Frequently Asked Questions

How Do I Know If My Sourdough Starter Is Dead?

Sourdough starter is “dead” and shouldn’t be used if there is any visible mold or if it has a musty, moldy scent. 

How Do You Bring A Sourdough Starter Back To Life?

If a sourdough starter hasn’t been fed in a long time, it can usually be revived by feeding it two times a day for several days. During this time, it’s best to keep the starter in a warm area, somewhere close to 80 F is ideal.

How Do You Fix A Weak Sourdough Starter?

The best way to strengthen a weak sourdough starter is by feeding it with whole rye flour and increasing feedings to two times a day.

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how to revive sourdough starter

How To Revive Sourdough Starter

  • Author: William Mack
  • Total Time: 72 hours 10 minutes
  • Yield: 150g 1x


Learn how to revive and strengthen a sourdough starter that’s been left unattended for long periods of time.


  • 300g Water
  • 300g Flour
  • 50g Sourdough Starter


  1. Take the sourdough starter in question and pour off or mix in any liquid that has separated on top.
  2. In a new, clean container, combine 50g water, 50g flour, and 50g sourdough starter. Mix well.
  3. Cover the container and let sit at room temperature (ideally close to 80F) for 12 hrs.
  4. After 12 hours, in another clean container, combine 50g water, 50g flour, and 50g of the new starter mix. Mix well.
  5. Cover and let sit for another 12 hrs at room temperature.
  6. Repeat this process 4 more times, for a total of 6 feedings over the course of 3 days.


After the first few feedings, your starter should start to double in volume within each 12 hour period. If your starter shows no signs of activity after several feedings, you’ll most likely need to begin a new starter. Using a digital scale will make this process fast, easy, and accurate.

  • Prep Time: 10 minutes
  • Fermentation Time: 3 days
  • Method: Baking
  • Cuisine: Sourdough

Keywords: How to revive sourdough starter, is my starter dead, strengthen sourdough starter

About the author

William is a classically trained chef, who spent years cooking in top NYC restaurants before bringing his talents home to Colorado. Now a stay-at-home dad, William has brought his passion for professional cooking home, where he continues to cook and bake for his wife and daughter.