How to Dry Sourdough Starter

I’m going to show you how to dry sourdough starter. Why? Because drying is the best way to preserve your sourdough starter for the long term.

an image of a jar full of dried sourdough starter chips

So you’ve jumped on the sourdough bandwagon, YAY! It’s so much fun, isn’t it?

But, there are times when real life interferes and you may not be able to bake for quite a while. Or maybe you want to share your starter with a friend who lives far away. Or maybe you just really hate to discard that discard.

The solution is this incredibly easy-to-do process for drying your starter. Once the starter is completely dried, your hard-won wild yeast goes dormant. The dried starter chips can then be stored indefinitely.

You can also pack some chips into a small envelope and mail them to a friend. I mailed some to my daughter who lives 3000 miles away. It’s a nice way to share from afar.

two photos showing fed and unfed sourdough starter ready for drying on a sheet pan.
I dried both a sourdough discard (left) and recently fed starter (right). Both dried well and were easy to revive. The discard did need an extra feeding before it was active enough to bake with.

FAQs about drying sourdough starter and preserving sourdough starter:

Can I dry sourdough discard or does the starter need to be fed?

I dried both a recently fed starter and sourdough discard which hadn’t been fed in over a week. I was able to revive both, but the dried sourdough discard did need an extra feeding before it was ready to use.

Can I use the oven to dehydrate sourdough starter?

Yes, but don’t turn on the heat. Use the convection fan without heat or just leave the tray in the cool oven with the oven light on.

Can I use a food dehydrator to preserve sourdough starter?

Yes. I used my dehydrator on the lowest temperature setting (90°F). It took about 8 hours for two trays of starter to dry.

Can I just leave the starter out in the kitchen to dry it?

Yes, it may take a bit longer but just leave it out at room temperature until it is completely dry and brittle. The time will vary based on the ambient humidity in your kitchen.

How long does dried starter keep?

Indefinitely.

How do I use dehydrated starter?

Add water and flour and wait for it to come back to life. Follow the instructions listed below. Also, you can grind the sourdough starter into a power which can be stored to rehydrate later or can be used directly in certain recipes.

a jar of dried sourdough starter chips behind a container of revived starter

If you find this information helpful, I’d really appreciate a 5-star review!

dried starter chips spilled from a jar
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4.92 from 137 reviews

How to Dry Sourdough Starter

Drying is the best way to preserve your sourdough starter for the long term.
Prep Time5 minutes
Active Time5 minutes
Drying Time1 day
Total Time1 day 10 minutes
Course: Baking How-Tos
Author: Eileen Gray

Equipment

  • Silicone Baking Mat or Parchment paper
  • Half sheet pan
  • Small spatula

Instructions

To dry the starter:

  • Line the sheet pan with a silicone baking mat or parchment paper. The silicone mat works best so use it if you have one.
  • Pour the starter onto the sheet pan and spread it out to a thin, even layer.
  • Place the pan in a cool, dry place, uncovered. I put mine into the oven with the convection fan on and no heat. Alternately, if you have a food dehydrator you can use that on the lowest temperature.
    show a food dehydrator with a tray of sourdough starter inside
  • After 18-24 hours check the starter. It should peel off the mat. If underneath the starter is still moist you can peel it off, flip over the pieces and leave them to continue drying. If using a food dehydrator check after 6-8 hours.
  • The starter is ready when it is completely dry and crisp. The texture should be like a potato chip which snaps when broken into pieces. You should have half the weight that you started with. If you started with 12 oz of starter you will get 6 oz of dried starter.
    broken chips of dried sourdough starter on a silicone lined baking sheet
  • Break the starter into chips and store in an airtight container at room temperature.
  • The dried starter will keep indefinitely. The dried starter chips can be ground into a powder.

To revive the dried starter: (yield 9 oz of starter)

  • Place 1/2 oz (14g) of starter chips or powder in a plastic or glass container. Pour 1 oz (28g) of warm water over the chips and stir to cover the chips with water.
    a plastic container with dried sourdough starter chips covered with water
  • Cover the container and set it aside until all the chips have melted into the water. This usually takes about 3-4 hours. The starter will not look active at this point.
  • Add another 1/2 oz (14g) of warm water and 1 oz (28g) of unbleached flour to the starter. Stir to combine. Cover and set aside for 4-6 hours. Now you should begin to see activity in the starter.
    a plastic container with rehydrated sourdough starter and flour being mixed in
  • Add 3 oz (84g) of warm water and 3 oz (84g) of unbleached flour to the starter. Stir to combine. Cover and set aside for 3-4 hours or until the starter has doubled in size and looks quite active.
    sourdough starter in a plastic container with mark showing how much it has risen
  • If after 4-6 hours the starter still seems sluggish, discard all but 3 oz of the starter and do one more feeding.
  • Use in your recipe as needed.
  • The amounts listed can be multiplied out to yield more starter.

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81 Comments

  1. 5 stars
    im very grateful for the detail in this topic. multiple ways to dry, store, use discard or fed and difference to get going again.
    thankyou.

    1. I’m not sure since I haven’t ever freeze-dried anything. If you try it let us know if it works.

    2. Yes you can freeze dry the sourdough starter. You will rehydrate it the same way as this recipe says. I freeze dried some and am going to fd more. Google freeze drying sourdough starter and you will find out you can do it.

      1. 5 stars
        Hello Janette,
        Thank you for your reply yes you can freeze dry starter, I would like to freeze dry discard also .
        I have about 1 qt of each, growing faster than I am using it, although I bake about every other day. I will get instructions on google.
        I appreciate your help.

  2. This idea is fabulous — never knew you could do something like this. No wonder our pioneer forefathers were able to travel so easily w/the starter. I’ll bet some cowboy cook used this idea, too! If no convection oven or dehydrator how do you produce heat for drying?

  3. Eileen,
    After two days, my discard is like rubber, rather than dry.
    Can I freeze this and still use it?
    I’m going away for three weeks and looking for a way to preserve my starter.
    Thanks,
    Bob

    1. Hmmm, where do you have the starter? Is it in a very humid environment. When drying starter I will sometimes peel the partially dried starter off the sheet and flip it over to let the other side dry out.

    2. @Eileen Gray,
      Yes, it’s summer here and pretty humid.
      I tried flipping it over and it didn’t dry any further.
      It’s like a duplicate of my silicone mat.
      Can I still use it? Or should I chuck it and start again?
      Thanks.

      1. Do you plan to use it as a starter? I wouldn’t store it in a container until it’s completely dry. Do you have a convection setting on your oven? You could try putting it in the oven. If you see any sign of mold on the starter or if you smell off odors I would chuck it.

    1. @Kathleen, So tell us what you are looking for. A commercial product, another way to dry it. portions?
      Inquiring minds want to know – esp if you have another, better method.

  4. Hi Eileen, We recently moved from IL to AL & traveled with the dried starter that I dried using your post. I had fretted how I was going to keep my starter going until I came across you blog. My first attempt to rehydrate was not successful & I had to throw it out. I was so sad that I couldn’t get it to work at first. I’ve had this starter since covid started so over 2 . I tried it again since I had plenty of dried starter but I also started a new starter at the same time just in case my original starter didn’t work again. I found that my house was too cool for the starter so I put both new & old starter in my oven (oven light was not on). Both new & old starters are active now but found that I still wasn’t achieving 100% hydration even though I was using the same amount of grams water & flour. I think the high humidity here is causing the starter to not be 100% hydration as it was in IL when I used the same amount of grams of flour & warm water. I have had to reduce the water to about 75% of the flour. Perhaps that will change as the season changes. Do you have any words of wisdom for me? I plan to try some of the powdered starter recipes you have given using my leftover dried starter. Thank you so much for post.

    1. Hi Deb. I can tell you it get pretty humid here in PA so I do work in humid conditions (although in an air conditioned house). What do you mean you have trouble achieving 100% hydration? If you feed with equal weights flour and water it should be at 100%. Do you mean the texture is different? Being in a new state the water could be different and even the flour is you don’t buy a national brand.

    2. @Eileen Gray,
      Good morning Eileen, thank you for your quick response. I use King Arthur flour and I weigh both flour & water by grams. When I feed my starter equal grams of flour & water the texture is not the same. It’s very loose unlike my starter when I was in IL. I made blueberry muffins this morning with my new starter & did have to bake them for a shorter period of time. When I bake I use electric oven & I use an oven thermometer so I do know my new oven was 350. I attribute the less cooking time to less water in my starter. It was humid in IL but in AL its much higher like 90+% humidity. Is that the reason for the texture to be so loose?

      1. Is this the new starter or the one from the dehydrated starter? The texture of my starter definitely changes as it ages. That is, when it peaks and then begins to recede it becomes looser. Maybe the starter is “faster” in the hotter climate.

      2. I am a flight attendant and have moved quite a bit and can tell you the places I have moved have made Hugh differences in the way food acts, bakes etc. so it is possible the conditions where you live maybe adding to the issues. Maybe a cheap dehydrator would help.

    3. @Deb,
      Hi Eileen, I just tried to send a reply & it just didn’t send. Both starters are really loose. I did use some rye flour in the new starter based on your suggestion. We are originally from AL but moved to IL as a very young couple for our jobs. I’ve always baked & cooked but didn’t start baking breads using sourdough until covid. I’m sure I’ll have issues with other things like macarons due to humidity. Thanks for your advice. Sorry for the delay but we are still unloading boxes.

  5. Hi! Just embarking on a sourdough voyage for the first time. I’m making my first starter ever today and was wondering- would the discards made in the process of starting a starting be viable for drying and saving? Or is this only after you’ve got a good starter going? I’d love to waste as little as possible! Thanks!

    1. I’ve had this question before. If you read through the comments you’ll see this response to Danielle. “…when I dried mine the top and bottom sides were different colors. The top got a kind of grayish/beige color and the underside was whiter. I’d be surprised if it would grow mold within 18 hours. Were you drying active starter or a more dormant discard? Discard can become grayish if it’s been unfed. Are there any off odors or does it just smell fermented? My first suggestion would be to let the underside finish drying and see what it looks like. I dried one of my trays at room temp for several days and didn’t get any mold at all. In the end, if you’re still nervous maybe you can just break off the discolored pieces and use the rest?”

  6. About 20, 25 years ago l bought what was claimed to be “oragon trail” sour dough starter. It arrived as a powder in the mail. The starter was weak. I messed around with it for a spellbut it was an underperformer.
    So, I dehydrated the starter, blended in into a powder, vaccumn sacked some small sacks with a foodsaver and tossed the lot into the chest freezer and moved on. About 3 months ago I removed a sac of the stuff. I used pineapple juice and water to revive it. It came back to life after more than 20 years in the slammer. It was sill sluggish but it was alive.
    So you can store this stuff long term, atleast the way I did it. Not sure about the freezing part but removing the O2 I think is a must. Iv had whole wheat flower stored in a sealed plastic bag with O2 absorbing packets stored in the freezer for 6 years, was still fine to use.

  7. I found some dried sourdough starter in my cupboard. Thank you for the directions. I am trying to revive it. Today 7 February 2021.

  8. please learn to provide proper units of measure. learn the difference between volume and weight and when to use which.

    ie: 14 grams of water?! your article while probably helpful reads ridiculously fast.

        1. not really. you can just use your regular kitchen scale to weigh your water.
          1 gr=1ml

          it’s not rocket science champ.

      1. @James,
        Why is that the worst comment ever?

        Eileen wrote: “I weigh water in grams all the time when I’m feeding my starter.”

        She didn’t say that measuring water in grams is the only way. She said that is her way to do that.

    1. For the case of water volume always equals weight and so it is proper to use either!
      And I find it actually easier if water is measured in weight since I am already using a scale for the sourdough starter and/or flour etc when baking and don’t need to take out a measuring cup just for the water. This way I’ll have more working space 😉

      And EIleen thank you for this how-to, I’m gonna make a few dry starter batches to send out for Christmas!

      1. I use weight specifically for this process because you’re working with such small quantities. Being exact with the measurements is even more important with you dealing with smaller measurement.

    2. I always measure my water in grams. One millilitre of water is 1 gram in mass (ok – pure and at standard temp, etc., but it’s close enough for the kitchen to always assume this). A recipe given in baker’s percentages assumes the water is being weighed just like everything else. In fact, the only time I don’t weigh an ingredient is when I have a recipe from an American that I know just scoops flour and gives the measurement in volume. I have found that in that case, weighing the flour will result in too slack a dough/batter — so I’ll follow the scoop method then. Otherwise — weigh everything — it’s much more accurate. I have verified the volume of several kitchen wet measuring cups I have and have found the markings to be as much as 1 fl. oz. off. That may not sound like a lot, but it can make the difference between success and mediocrity.

    3. no need to be rude., Instead of learning about sourdough you need. learn to be polite
      If you are unhappy with the way the author writes recipes simple go to another site.
      Sourdough really isn’t rocket science.
      .It has been around for centuries and they certainly did not have the conveniences for measurement that are available today
      I appreciate the authors willingness to share her thoughts and ideas

    4. @ponyboy,
      It seems you haven’t been able to pass elementary school. Let me enlighten you. The SI standard of weigh based on the volume of water. 1 liter of water in room temperature is 1 kg. 1 kg = 100 dkg = 1000 g
      1 kg water = 1000 ml
      1 dkg water (10 g for the weak in mind) = 1 cl (10 ml)

    5. @Impatient_Teacher, no need to be insulting. Many if us have years of valid experience without a scale. Scales are useful but much excellent baking had been done for centuries without one. Metrics have not always been taught in school..thank you for your help

    6. @ponyboy, this is a very valid measurement. As we know 1 liter of water equals 1000 g or ml of water. It is just much easier to measure 14 g on a kitchen scale than 14 ml in an container. Possibly on a not plum surface.

    7. @Liz Reynolds, I never measure my starter feedings and all four of them are alive and well…so many happy bubbles. I go off of texture, look, and smell somehow I imagine 100+ years ago cooking in a cast iron pot over an open fire they didn’t really have a gram scale:-)

    8. @Eileen Gray, I weigh the ingredients in grams as well.. I follow your instructions for dehydrating and rehydrating my sourdough starter

  9. Thanks so much for this post! I hope you can help!

    I dried my starter in a thin layer on parchment and kept it in my oven (off) for 18 hours. I just peeled it up to flip any still moist pieces and some moister bits have almost a brown but greenish tint on the underside. Is this normal? It doesn’t look like mold, but just made me nervous…

    1. It’s hard to say without seeing it, but when I dried mine the top and bottom sides were different colors. The top got a kind of grayish/beige color and the underside was whiter. I’d be surprised if it would grow mold within 18 hours. Were you drying active starter or a more dormant discard? Discard can become grayish if it’s been unfed. Are there any off odors or does it just smell fermented? My first suggestion would be to let the underside finish drying and see what it looks like. I dried one of my trays at room temp for several days and didn’t get any mold at all. In the end, if you’re still nervous maybe you can just break off the discolored pieces and use the rest?

    1. @Jenni, Since I first wrote this article I bought a dehydrator and used it to dry my discard. I set it to 90 degrees and it took about 8 hours.

  10. I have a convection oven, but am not aware of a way to turn on the fan without the heat. How did you do this on your oven? Do you just have a setting on it for fan only?

    1. I can turn on the fan without heat in my oven. You could also just leave the tray out at room temperature for a couple of days.

      1. Question: instead of saving the flakes, can I grind them into a powder? Easier to store and keep still using weight to measure.

        1. Yes, in fact, I’ve been playing around with ground starter. I use a spice grinder for it. You can also use a mini food-processor.

  11. please help me – i dehydrated my starter, then tried to re-hydrate– it failed(after 3 days of feeds- i gave up.
    so, my best guess is that my oven with the light on was too hot during the drying stage– and cooked iT!!! with the light on my oven gets about 87-90 F
    please tell me what would be the max temperature for this?
    Thank you for all your shared info.!!!
    Connie

    1. I don’t think that temp range would kill the yeast since I use water over 100F for making bread. Try dehydrating at room temp (it will take a few days) and see if that works better. I found that it also made a difference how active my starter was when I dried it. Discard took a couple of feeding to become active. Did you use warm water for rehydrating?

    2. @Eileen Gray, yeast actually won’t die until about 140 degrees. I’m not sure about the beneficial bacteria also present in the starter. That said, I dried mine in the oven with the light on, mine will get up to about 105 if I leave it on but I prefer to keep it under 90. I don’t think 80-90 would kill anything.

  12. I am currently experimenting with Sauerdough and I am really glad that I found your site. Thank you for the detailed instructions for drying the starter .In the past I have made “krümel – starter” and just a while ago I debated if I could vitamise the crumbs and if it would be easier to start the next batch ..
    We have brought up a large family and most of our children and their partners have embraced the “good old fashion taste” and making lovely home baked goods ( including bread )
    It is indeed lovely to sit together over a meal and encourage each other with more insights and new recipes .
    Looking forward to browse through your recipes , THANK YOU , Ose Krüger from Adelaide / South Australia

  13. I have dried my starter as you suggest and it is now in a jar.
    My question is, would it be possible to grind the flakes and use them like a normal dried yeast?
    As it will not be as strong as bought dried yeast I would double the mmount used..
    What do you think?

    1. I’ve been doing experiments with ground dried starter. I’m not ready to publish yet, but I am working on it.
      P.S. Great minds think alike, I guess!

    2. I don’t think using it directly in a recipe would work — it can take 12 hours or more for a dehydrated starter to “wake up” and become really active. Remember — the dried yeast we get from the store is a strain that is specifically chosen because it wakes up fast, the yeasts in our starters are wild.

      That being said, grinding may well save hours off of the front end of waking up the starter because it won’t take as long to rehydrate. I haven’t done this, but it seems reasonable. Also, if grinding in a food processor or Vitamix, use several short pulses — allowing the machine to run too long will heat the dry starter, possibly killing our dormant yeasts and bacteria.

  14. I have wanted to use sourdough starter but am not always home to feed so i disregarded any reCipes using starter. Yeah. Thank You for your post about drying starter. I am a new subscriber of your blog. I found it when looking for a buttermilk bundt cake recipe. Lucky me. I can already see how informative and useful it will be and can’t wait to starting baking. Not only do you recipes look great but the informative intro. Will make me a much better baker.

    1. I have had great success keeping small amounts of starter in the refrigerator when I’m not baking every couple of days. I mix 20g starter with 20g flour and 20g water Leave on the counter for an hour and then stick in the refrigerator. Even after several weeks of no feeding, it usually wakes up after a feeding or two. Just take it out a day or two before you want to bake, stir the hooch back in, feed 60g flour and 60g water with no discard, then 180g flour and 180g water about 12 hours later (sooner if it has reached its peak), again with no discard. Then feed normally. In the refrigerator, I always keep it in the coldest section, which is about 38F or 3C.

    1. I bought an old (1970s) book about bread and inside is a packet of dried starter. I’m tempted to see if it works….also scared I will poison myself….

    2. @Jaki, I have a package of dried San Francisco stated that is 35 years old!! I’m trying to revive it right now. My research brought me to this site. We’ll see how it goes : )