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Sourdough Starter Primer

Reviving a Sourdough Starter

This is a part of our "Sourdough Starter Primer", an in depth look at how to start, maintain, store, revive and even use a sorudough starter.

A systems analyst's mantra says, "It takes a consistent process to produce a consistent product." I learned this when I was a programmer and systems analyst. I had a graduate course in it when I was running a bakery. And I've had it reinforced with many letters I've received over the years I've been running the web site. People don't pay attention to their starter. One time, the bread rises in 4 hours and tastes great. Another time it rises in 2 hours and has no taste. Another time it takes 16 hours, there's hardly any rise, and the bread is as sour as some kids nasty sourstuff candy. And then the people become sourdough dropouts. The first key to consistent sourdough results is a consistent starter.

This page has two focuses. One is the normal revival of a refrigerated storage starter to turn it into the consistent starter you need in order to get consistent results. The other focus is an attempt to recover a starter that has been ignored for far, far too long so you can rehabilitate it. Let's talk about the easy case first.


Reviving a Healthy Storage Starter

In the Storing a Starter page we talk about how to store a starter. If your storage starter was fed just before you put it into the refrigerator, and it has been in storage for less than a week, you can probably just use the starter. Measure it, put the unused storage starter back in the refrigerator, let starter you are going to use come to room temperature and use it. Remember that a starter at room temperature needs to be fed no less than twice a day, so don't leave this starter out overnight, or for a similar length of time, without feeding it. It has been eating the available starch in the starter while in the refrigerator and if you're going to let it sit a while, it needs a real feeding.

If your storage starter has been in storage for more than a week, you really need to take a little more time reviving it whether you intend to bake with it or it's just time to revive it to make sure it's healthy. I like to feed the starter for at least three days before using it or putting it back in storage. I'll take a teaspoon (about 6 grams) of storage starter from the jar in the refrigerator and put the jar back in the refrigerator. You can use the starter in the refrigerator, a teaspoon at a time, for about a month before you need to revive it. Once the storage jar is back in the refrigerator, I add 1/4 cup (about 50 grams) of water to the teaspoon of starter and vigorously stir them together. Then I add 1/2 cup (about 50 grams) of flour (if you are using 1/2 cup, the flour should be sifted and spooned into the 1/2 cup measure) and stir vigorously again. Twelve hours later, I add the same amount of water and flour again.

If I am feeding the starter to revive it, I'll start discarding 1/2 the starter and then feed another 1/4 cup water and 1/2 cup flour every 12 hours or so. When the starter is doubling nicely between feedings, I'll feed it one more time, clean out the storage jar, put the freshly revived starter into the jar, and then put the jar back into the fridge. Again, the key success strategies are to feed the starter until it is doubling between feedings, to fill the cleaned jar no more than 1/2 full, and to refrigerate immediately after you feed the starter.

If I actually want to bake with the starter (remember baking? the point and goal of the exercise?), I don't discard any more starter. Instead every 12 hours I double the amount I am feeding the starter. So, my next feeding is 1/2 cup of water (about 100 grams) and 1 cup (about 100 grams) of flour. Twelve hours later, 1 cup (about 200 grams) of water and 2 cups (about 200 grams) of flour. My goal is to double the starter with each feeding so I'll have enough to bake with in two or three days. If you weigh your ingredients it is very easy to calculate how much starter you will need and how much each feeding should be so you'll have enough starter in two or three days with no wastage. The goal here is to have enough active healthy starter to bake with in 3 or so days with little or no starter left over.

Please note, the amounts in the volume measurements and weight measurements are not the same.  In each case, I am using a convenient measurement.  There are actually 130 grams of so of flour per cup, and 238 grams of water per cup.  It's easier to use even amounts where one can.  I don't like recipes that call for 1/4 cup less 1 TBSP, or 1/4 cup plus 1 TBSP.  Yeah, sometimes things work out that way, but I'd rather avoid them.


The Ugly Tale Of The Long Forgotten Starter
It's easy to revive a starter that has been well cared for. You know what they say about an ounce of prevention. However, sooner or later, you'll find a jar of starter that you forgot but time did not. And you really want to revive the starter. Can it be done? Usually, the answer is yes.

But there are some caveats here. Dr. Ed Wood, who knows more about starters than just about anyone alive, has said he's never had a starter he couldn't revive. It must help to have medical training. However, other people point out that it's not always clear if the starter your revived is the one you started with. Kinda like in Stephen King's book "Pet Semetary," you can wind up with a starter that's similar to what you had, but not quite the same. And there are a few conditions that make your starter not worth the trouble of trying to revive it. So, let's look at the science experiment you are pretending used to be a sourdough starter and see what we can do with it.

An Important Note - I get a fair number of emails asking if I think a starter that's been stored like this, or forgotten SO long can be revived. I really can't predict if your starter can be revived. Was it healthy before it was ignored? Was it already damaged? In the end, the starter will tell you by reviving or not reviving. I used to answer ALL my email. However, at best I don't answer it as quickly as you - or your starter - would like. However, I am sure that if you wait a week for my email before you start trying to revive your starter, your odds just went down. When in doubt, try to revive it! It's a little flour and water and a little time. It's worth the risk, so just do it!

Our first goal is to get a good sample of the old starter. How we do that depends on the condition of the starter. If there is a layer of liquid on top of the starter, it is called hooch - old miners used to drink it when they were desperate for a drink. Yes, it has low-grade alcohol in it.

Was there mold on the hooch? Is there mold on the top of the starter? If not, smile and skip to the next paragraph. If there is, go to the silverware drawer and get a handful of spoons. Mold is normally a surface condition, so we'll try to get some good starter from lower levels of your starter jar. Start by scraping off the mold, being very careful not to stir the starter - you'll only stir the mold into the starter. When you think it's all gone, get a clean spoon and scrape a bit more starter off the top. Now go on to the next paragraph....

If there was non-moldy hooch on top of the starter, just pour it off. We are trying to revive a long forgotten starter, and the concentration of alcohol and other waste products in the hooch won't help with the revival. With a fresher starter, we might stir it back in. But not this time.

Chances are good that the top of your starter has discolored, having turned gray from exposure to air or stuff in the hooch. You'll want to use a clean spoon to remove the darker layer, revealing a lighter colored layer beneath. If you just removed the mold, chances are good you don't need to worry about the discolored surface layer - it was scraped away with the mold.

At this point, you should have a light colored layer of starter exposed, free of hooch and mold. Use a clean teaspoon to transfer a teaspoon (about 6 grams) of the starter to a clean bowl. Reseal the jar of starter you are trying to revive and put it back into the refrigerator - sometimes the first attempt at revival doesn't work, and you'll need to go back to that starter.

Now add 1/4 cup of water (or about 50 grams) and stir the starter very vigorously. Add 1/2 cup of flour that was sifted and spooned into the 1/2 cup measure (or about 50 grams) of unbleached, unbromated white flour and stir again. This is very important, even if you are a whole grain enthusiast. Whole grain flours have many organisms on them that would compete with the organisms in the starter you are trying to revive. We want to give your starter the best chance of reviving. Whole grains are great for starting a starter, but not for reviving one.   Twelve hours later, another 1/4 cup (50 grams) of water and 1/2 cup (50 grams) of flour.

Before we continue with reviving the starter, when I suggest discarding starter in this article, I really want you to discard it.  I don't want you to save it in a jar for later use.  Many people don't like discarding starter, and I am one of them.  Starter is made of food, and discarding food is wasteful.  However, at this stage it isn't clear what microorganisms are active in our starter and in the interest of safety, I'd rather not eat, or encourage you to eat, anything made with your starter at this point.  Once your starter is again well established, then you can again save discarded starter for other projects, such as those mentioned in our page dedicated to recipes using discarded starter.

Now, start the usual maintenance feedings.  Since the volume of starter is where you want it, every 12 hours discard half the starter and feed the remaining starter another 1/4 cup of water and 1/2 cup of flour - or about 50 grams of each.  Again, when I said "discard" in the beginning of this paragraph, that's what I meant.

Your starter should take off in 2 to 3 days. If it is slow, or if it isn't responding, switch to three feedings a day, with each feeding being enough to triple the size of the starter. Do that by discarding 2/3 of the starter and adding 1/2 cup (100 grams) of water and 1 1/2 cups (100 grams) of unbleached unbromated white flour. If the starter doesn't start working well in another 2 days of this process, it's time to pitch this starter and go back to the storage starter in the fridge and start  over.

There is one condition that seems to be irreversible. Sometimes you mix up a dough with your starter and the dough quickly gets very soft, it turns into a liquid. And the starter has a strong smell of acetone, or cheap fingernail polish remover. If this has happened, bacteria that can eat the protein in your starter have taken it over. Normally starch-eating bacteria are in your starter. If you don't feed it often enough, the protein-eating bacteria can take over.

Do you remember back in the Starting A Starter page when I talked about how a starter was like a weed patch that you were cultivating? At this point, one of the weeds has again taken over. And it is a very hard weed to eradicate. I know of two people who were able to beat back the protein-eating bacteria and have their old starter back. However, the other guy and I both found that the next time we skipped a starter feeding the bad bacteria took over again. The starter was undependable and unstable. Pouring it down the drain and starting over was the only real answer for me.

It is worth mentioning that the above paragraph has prompted more than a few conflicting comments from experts. Didier Rosada, who has trained a number of Coupe du Monde de Boulangerie world champion baking teams, says that you are better off just pitching it and starting over. Debra Wink a well known hobbyist baker and biologist says she's recovered starters like this in 7 to 10 days. My view - in 7 to 10 days I can start a new known good starter, so I'd rather just start over.

After an aggressive feeding campaign to get a starter back alive you may find that the starter just doesn't have the taste it used to. Usually that is because the yeast is dominant in your starter. Rapid feedings seem to favor the yeast. Feeding the starter part whole wheat or rye flour will help restore the balance. About 5% whole wheat and 95% white for a few feedings seems to take care of this in a few feedings. If you are measuring by volume, put a tablespoon of whole wheat or rye flour in each measuring cup, then fill them with white flour. The starter should return to normal in short order.

Once you think your starter is doing well, make some bread with it. If the bread is OK, then your starter is probably OK, so you can pitch the rest of the stored starter you've been trying to revive and save your recovered starter in the fridge.

An ounce of prevention is worth several pounds of flour.... so I hope you never have to use the ugly forgotten starter recovery notes!


19 thoughts on “Reviving A Sourdough Starter”

  1. Hello! I got a starter from a friend less than a month ago and LOVE IT like a pet. I have never missed a feeding – was feeding just one T of flour and water like her guru suggested. It was fine until I left it on the stove when I baked my sourdough pizzas and it got way too hot. Now I’ve changed my protocol to discarding and doing 1/4 cup each but I still have hooch and it is definitely not doubling. Did I mess it up too much by heating it too hot on the stovetop? I will switch to white flour like you suggested and keep trying but if you think I need to start over I will. Thanks!

    1. Well, leaving it on the stove didn’t do it any favors. When you feed 1/4 cup of flour and 1/4 cup of water you are feeding it too little and the starter is too thin. I usually recommend feeding equal amounts by weight, not volume (cups). When you feed it too little, you will get hooch.

      However, the hooch suggests that it is alive, so all is not lost.

      If you have scales, I’d weigh 1 part of starter and add 1 part each of flour and water. Or, 100 grams of each.

      If you don’t have scales, I’d measure 1/4 cup of starter, add 1/4 cup of water, and then add 3/8 cup of flour. It’s a reasonable approximation.

      Feed twice a day, or about every 12 hours, and it should be better in a few days.

      Best wishes,

      1. I just began my first starter, on day 3 it had absolutely exploded overnight, well over doubled in 8 hours, and I switched from 24 to 12 hour feedings. In the 3 days since then, it has risen less and less each time and now won’t rise at all. It still smells super tangy. What am I doing wrong?

          1. I started with whole wheat and switched to all purpose flour for the feedings. I’ve been doing 113g water and flour every 24, and then every 12 hours.

          2. Hi again,
            I’d asked which of my methods you were using so I could give you more focused advice. It seems you aren’t using any of my methods, so I’ll suggest you look at the overall “Starting a Starter” page in the Sourdough Starter Primer which will help you better understand what’s happening in your mixing bowl and then look at “Starter, My Way” which is probably the closest to what you’re doing.

            Using a whole grain flour to start with is a good thing, it helps kickstart the starter. However, you seem to have run into two pitfalls. When you switch to white flour the starter slows down dramatically. I don’t just suddenly switch over, I start with a feeding of 3/4 whole wheat and 1/4 white, then half and half, then 1/4 whole wheat and 3/4 white. This seems to reduce the starter’s shock.

            Also, based on what you wrote, it seems that you aren’t discarding any starter. How much we feed a starter is based on how much starter we have. Imagine having a Great Dane puppy. When it’s weaned, 1/4 cup of puppy chow will probably be enough. However, if you keep feeding it 1/4 cup a day, it will be really hungry a few weeks on as it grows and needs more food.

            I have, for a long time, recommended feeding 2 parts of starter to 1 part each of flour and water, by weight. This worked well in the mountains, but my starters are too acidic these days, so I am suggesting 1 part starter to 1 part each of flour and water, by weight. Or, as some write it, 1:1:1. So, to 100 grams of starter, add 100 grams of water and 100 grams of flour. This will triple the size of the starter with each feeding.

            This causes its own problems. If you keep tripling the amount of starter, it won’t take many days to fill a swimming pool with starter if you don’t do something. And that something is to discard all but 1/3 of the starter so the amount of starter stays pretty much constant. If you’re like me, you don’t like throwing away food. However, in the early days it helps to think of your starter more as a biology experiment than food. Once your starter is stable, you can set aside the starter you would otherwise discard and use it for other things. I have a number of recipes for using discarded starter. However, there are ways to avoid discarding starter altogether, which makes more sense to most folks.

            Hope this helps,

  2. Thank you Mike!
    I am discarding starter and using the 1:1:1 method, sorry I forgot to mention that.
    I will take note of what you’ve suggestef regarding shock however, and take a look at your methods. I was suspecting perhaps it didn’t like the APF for some reason… Will keep working on it!

  3. Hi! I was given a dormant whole wheat flour starter, and I read that you should always use the same type of flour to revive a starter before switching it. But I wasn’t sure if your instructions meant that you should use plain flour to revive regardless of the original type?

    1. Years ago Yamaha advertised that their loudspeakers were made from the same wood as their guitars. It wasn’t clear that the same would would be a good choice for a sound reproducer and a musical instrument. Would the wood add or change the sounds that the speaker was supposed to reproduce?

      Similarly, when I revive a starter, I want to give it the best chance it as of reviving. Many flours have their own component of yeast and bacteria on it which would compete with what is in the dormant culture. To reduce that Darwinian struggle, I suggest as sterile a flour as possible. And that is white flour, either an all-purpose or bread flour. Once your starter is revived and healthy, you can switch over to whatever flour you would normally use.


  4. I accidentally stirred my hooch back into the starter before coming to your page for advice on reviving a forgotten starter. It was left out, at room temperature, covered, for a week without feeding. Smells mostly yeasty with a little stinky feed smell but no mold and some bubbles happening.

    1. Starter is far more resilient than most people think.

      Just follow the procedure in the “The Ugly Tale Of The Long Forgotten Starter” section and your starter will probably be OK.


  5. I agree, Mike! I just revived my years-long-neglected starter from my fridge–3rd time I’ve done this! To those who are unaware, it will basically look like your other food leftovers jars of unknown origin. Black, grey, crusty, mouldy….

    But, follow the instructions above for “The Ugly Tale Of The Long Forgotten Starter” and you should be fine! I always get mine back into a healthy beast again, thanks to Mike!

    Hands down, this is the best resource for sourdough care, and I recommend these instructions to anyone just getting into sourdough.

  6. I had some starter that was left in the fridge for several weeks. I used the method above to liberate about a teaspoon of the starter (there was a 1/4 inch of hooch on the top, and some slight discoloration, so I poured it off and I used starter that was lower in the jar). I’ve been cutting the started down by 2/3s each time, leaving 100g, then adding 100 grams of each water and flour. It continues to double in about 12 hours, so it seems good. However, when I discard an mix new, the result is like a thick pasty dough, and when it gets to double the amount the starter is light and fluffy with 1/4 to 3/8 inch bubbles on top, is my starter okay? I ask because within this page it discusses the starter turning like water – mine’s not like water, but a lot lighter and fluffier than it was when originally mixed. Before I left it in the fridge for too long it would generally be close to the same consistency after feeding and sitting for a day (it would rise, but didn’t get a much looser). One last thing, As I was going through the recovery process, I did it all at room temp – did not refrigerate at any time. Hope that was as intended. Thanks.

  7. I’m just starting the “ugly tail of the long forgotten starter” process for my starter I neglected for 2 months. I’ve completed step one last night and just added the second 50 grams each water and flour. I want to confirm this is all to be done at room temperature?

    Also, since it is winter and we’re running the heat in the house, 67 or 68 degrees, can this affect this process? Do you recommend I find fan area in my home with a cooler temperature?

    1. Hi Colleen,
      Starters are temperature sensitive. The slow down at cooler temperatures, and speed up at warmer temperatures. When you get much below 65F (18c) they slow down to a point where they are aggravatingly slow. When you heat them much above 95F (35C) you are risking the starter developing off flavors. To summarize – any time you are feeding a starter, it should be at room temperature.

      As you can imagine, things slow down too much in the fridge. That’s why we store them in the fridge, to slow them down so we don’t have to feed them twice a day.

      I would not look for an area cooler than the 67 or 68 you mention being in your house. If you become impatient, you can look for a warmer area. On top of the refrigerator is often a warm spot, in your oven with the oven light on is a warmer place, a proofing box or yogurt maker can also work.

      Hope this helps,

      1. Thank you so much. Things were moving a little slow so I ended up going to the three feedings a day as described and looks like it’s responded nicely. I’m going to start baking. Do you recommend sticking with the unbleached flour or can I start using my whole wheat flour for this? May test with one loaf of each.

  8. I just found you, Mike. I love how you share you craft and passion for sourdough. I am just reviving my sour dough chips from two years ago. I will try measuring by weight this time!

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