Why Is My Homemade Yogurt Slimy? Causes, Fixes, and Prevention

Sneak Preview: Find out the cause of your slimy yogurt, how to avoid it in the future, whether it’s safe to eat, and more.

My Stringy Homemade Yogurt and How to Avoid It--A picture of stringy homemade yogurtPin

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The first time I made slimy yogurt, I was shocked. I expected creamy, spoonable goodness but got a stringy mess instead. Determined to figure out what went wrong, I went into full investigation mode.

There was no way I could share that batch—it would’ve ruined my yogurt-making reputation! So I dug deep to find the cause and, more importantly, how to prevent it. If you’ve run into the same problem, keep reading—I’ve got answers! Because homemade food should be food worth sharing.

Thanks for the great site. I came here because I made my usual yogurt with 1 liter of UTH milk plus 1/2 cup of milk powder. Came out stringy and slimy, but the taste is fine. Now I understand why.”
–KM

What Causes Slimy Yogurt?

perfect yogurt compared to stringy yogurtPin

If your homemade yogurt has a stringy or slimy texture, the most likely cause is wild yeast contamination.

  • Wild yeast is airborne and can disrupt the bacterial balance in your yogurt.
  • Using a starter from a slimy batch will continue to produce the same undesirable texture.
  • Heirloom starters are more resistant to wild yeast than store-bought yogurt starters.

Choosing the Right Yogurt Starter

traditional starter vs supermarket yogurtPin

The type of yogurt starter you use plays a major role in preventing slimy yogurt. There are two main types:

  1. Grocery Store Yogurt as a Starter
    • Typically contains only a few strains of bacteria, making it more vulnerable to wild yeast.
    • Over time, these strains weaken and may produce inconsistent results.
    • Best practice: Refresh with a new container of yogurt every 3-4 batches to maintain stability.
  2. Traditional or Heirloom Yogurt Starters
    • Contain a diverse blend of bacteria that make them more resilient.
    • Designed to be reused indefinitely with proper maintenance.
    • Less likely to be affected by wild yeast, making them a more reliable option.

“The difference with a traditional starter is that it is composed of more varied bacteria so that when one strain falls prey to phages (a virus that infects and replicates within bacteria), there will be others to take over and maintain fermentation.”Sandor Ellix Katz from The Art of Fermentation(paid link)

👉 Learn more about choosing the best yogurt starter here.


How to Prevent Slimy Yogurt

  • Start with a reliable yogurt starter – Traditional starters are best for preventing contamination.
  • Use a fresh starter – Avoid reusing a starter from a slimy batch.
  • Avoid cross-contamination – Some recommend avoiding baking yeast bread the same day you make yogurt. (I do this weekly but it has never caused a problem since I started using a traditional starter.)
  • Refresh your starter every 3-4 batches – Store-bought yogurt weakens over time as a starter.
  • Keep utensils clean – Wash all equipment thoroughly to reduce contamination risks. I don’t think it’s necessary to sterilize all of your equipment. See the quote below.

“But generally sterilization is unnecessary. Incidental microorganisms that inevitably are found in non-sterile though clean environments cannot generally gain a foothold in a fermentation substrate. This is because the ferment either has its own indigenous microbiota (as in sauerkraut and traditional wines), or has had a critical mass of cultures introduced (as in yogurt, tempeh, and most contemporary beers). We are living in a microbial world, and these processes all developed under decidedly non-sterile conditions.

Traditional mixed culture starters tend to be stable under favorable conditions. Only in the realm of propagating pure-culture mold spores, which tend to pick up more bacterial strains with each successive generation, have I found sanitization beyond mere cleanliness to be warranted.”

Sandor Ellix Katz from The Art of Fermentation(paid link)

Is Slimy Yogurt Safe to Eat?

  • Generally, yes, if it smells fine and has no mold.
  • The texture will be different, and the taste may be slightly yeasty.
  • If it has an off smell, discard it.

Can Slimy Yogurt Be Fixed?

  • No, once yogurt turns slimy, there’s no way to reverse it.
  • Do not strain it—this will only worsen the texture.
  • Do not use it as a starter for a new batch.

What to Do with Stringy Yogurt

If you don’t want to eat it as is, consider using it in:

  • Smoothies
  • Baking (as a substitute for buttermilk)
  • Cooking (soups, marinades, or dressings)

Viili Yogurt: The Exception

Viili is a Finnish yogurt variety that is naturally ropey and stringy. If you enjoy the texture, you might want to try making Viili intentionally.


Frequently Asked Questions

  • Why does my yogurt have a slimy texture?
    • Wild yeast contamination or using a starter from a previous slimy batch.
  • How do I prevent my yogurt from turning stringy?
    • Switch to a traditional starter, keep your equipment clean, and replace store-bought starters every few batches.
  • Can I use slimy yogurt as a starter?
    • No, a slimy starter will produce more slimy yogurt. Always start with fresh yogurt.

For more yogurt-making tips, check out this “Question and Answer” guide to making thicker, creamier homemade yogurt!


Final Takeaway

  • Your yogurt starter matters! Traditional starters are more resilient and resistant to contamination, making them the best choice for long-term yogurt-making.
  • If you use grocery store yogurt as a starter, refresh it often. The bacterial strains weaken over time, making contamination more likely.
  • Slimy yogurt is usually caused by wild yeast. Keeping equipment clean and limiting exposure to airborne yeast can help prevent it.
  • Once yogurt turns slimy, it can’t be fixed. Start fresh with a new, uncontaminated starter for the best results.

Questions? Email me: Paula at saladinajar.com. Hope to see you again soon! 

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39 Comments

  1. Wren Passerine says:

    I made yogurt several times years ago with store bought yogurt as my starter. I wanted to start making it again from scratch to save money ($10 for a quart of plain, organic whole milk Greek yogurt…argh!) and the same day I set this batch to culture, I happened to be trying out making two separate sourdough starters. I don’t like sour yogurt so I set it for 8 hours then strained it so it would have that Greek yogurt consistency. It smells fine and if I don’t think about it, I don’t notice the stringiness of the yogurt. I’m grateful to know why this happened. I had been wondering if it was due to the grocery store yogurt I used as a starter (one that was priced at $6.99 that I hadn’t tried before vs $10) but now I understand that wasn’t the cause. The yogurt wasn’t stringy. I have two sourdough starters (one with einkorn wheat and another with rye, the latter is very active), and I definitely think based on your article that this is the culprit. What do you recommend I do if I plan to make yogurt weekly and have a sourdough starter always going? My daughter and I eat copious amounts of both. Thanks for your input!!!

    1. Hi Wren,
      I sent you a personal email with a detailed answer. If you don’t see it, you might check your junk mail. paula

  2. mine was from my kombucha starter , having nearby ferments will affect it!

    1. Hi Skylee,

      I don’t make kombucha, but I can only imagine. The bacteria that powers these wonderful foods don’t always play nice. Thank you for writing.

  3. Gufrana Khanam says:

    This article is helpful. I’m a nutritionist and I always have an exciting time making home made yogurt. This time the yogurt turns out stringy and slimy. The weather here is monsoon here so possibilities are that the yeasts have done its work. I was anxious whether to eat it or not as its perfect in taste and smells good.

    1. Hi Gufrana,

      When it still smells good and tastes fine, it is safe to eat. You probably got some wild yeast that didn’t get along so well with the other yeast in your yogurt.

      I’m curious, what did you use as a starter? If you used your last batch of yogurt, what did you use in the beginning to make the “mother” yogurt. If it came from the grocery store, most people don’t recommend you use it for succeeding generations more than 3 or 4 times. The grocery store yogurt is engineered for the highly controlled environment of a factory. When we use it in our kitchens that aren’t so highly controlled, it can go south pretty easily. Some people say you should start over month with a new jar of yogurt from the grocery store. An alternative is to use a freeze-dried yogurt starter that is much hardier and can make infinite batches of yogurt if it is used regularly.

      Write back anytime you have a question.

  4. hey , I just made a batch and it doesn’t smell bad or have a sour taste but I am curious about the protein content..woukd it have changed ? like does the thicker one have more protein than the slimy yoghurt?

    1. Hi Ava,

      Nice to hear from you. I am not a food scientist so I can’t get technical here, but let me take a stab at your question.

      There is only so much protein in milk as it comes out of the cow. Making milk into yogurt does not create protein. Thicker yogurt has more protein only because some of the whey has been removed or some of the liquid has evaporated. Whether it’s slimy or not will not affect the protein content.

      You can eat slimy yogurt and still get all of the protein. The main difference is that the texture is off, probably because it has been “infected” by some rogue yeast, which upset the delicate balance of the desirable yeasty bodies in the starter.

  5. thanks for the info! I’ve been making yogurt for about five or six years, and I’d been recycling an old grocery store yogurt for over half a year I think with no issues, but we ended up eating the last of it before making more. I used a fresh grocery store starter and got stringy yogurt for the first time ever.

    1. Hi Karen,

      I’m sorry about your stringy yogurt. Sounds like bad luck. Using grocery store yogurt is so unpredictable. When I used it, I could go months like you did with no trouble. Then, other times, I wasn’t so lucky.

      Since I switched to the freeze-dried, the only times I’ve had to start over is when we do what you did. Ate it all without saving any for the next batch. Oh well…it happens. 😀

  6. Glenna Lindsey says:

    I mixed whole milk with about a cup of buttermilk let it sit on counter few hours, then put in fridge a week. I used it to make banana bread. The buttermilk after shaking it up was stringy. It poured like mixed eggs for scrambled egg. I read it is safe. But pour it out afterwards. I hope I am ok to eat it. Thanks

    1. Hi Glenna,

      I have never tried this myself so I can’t advise you one way or the other. My general principle with yogurt is this: If it looks good, smells good, and tastes good, it’s probably OK. Beyond that, follow your instincts.

  7. MamaBaines says:

    This was my first attempt at yogurt. I am lactose intolerant, but I have purchased and drank goat kefir with no problem. I used goats milk with cow yogurt starter. Do you think that crossing the 2 milks was the issue creating my stringy yogurt?

    1. Hello,
      Figuring out the cause of stringy yogurt can be a guessing game. Somehow, the starter bacteria has gotten out of balance. How fresh was the starter? For best results, it should not be more than a week old. I would try again with new starter. You may have to do some experimenting. Is there a chance you are using too much starter?

  8. Great ideas to prevent my yoghurt from getting slimy

    1. Thanks, Amira. Hope you found it helpful.

  9. Paula, you are a fountain of knowledge about making yogurt. I’ve binge read about 3 or 4 of your posts related to making yogurt and I’ve learned so much. Thank you so much for sharing your knowledge.

  10. Made my second ever batch of yogurt, and as I was getting it into the strainer noticed it was slimy, gooey, etc. Didn’t think much of it at the time, but now a day or so later, considered that maaaybe I’d done it wrong enough that the milk just spoiled, and that the spoonfuls I fed my cats might have been a poor decision. That latter thing still might be true, I have no idea if/how wild yeast affects cat digestive systems, but I figure it’s prooobably not too much?

    I don’t eat yogurt plain much anyway, was planning on adding fruit & plenty of sugar to snacking yogurt, and the rest will be replacing cheese, sauce, butter, etc so hopefully it doesn’t turn out too bad.

    I also have to imagine this happened bc rather than use only a freshly opened gallon, I thought I’d use the milk from the previous week before it went bad. Lesson learned!

    I’m curious if I could make my own heirloom starter, of sorts. Next batch I’ll start fresh again to avoid the yeast, ofc. Batch after that, my idea is to use some of my previous batch, but *also* add in a bit of store bought–a different brand than before, with different strain of live cultures. No idea if that’ll work.

    1. Hi Flora,
      How did your “slimy” yogurt smell? If it smells fine, it should be safe to eat–just a weird texture on your tongue. Baking with it or feeding the cats is a great idea.
      I’ve never experimented with making an heirloom starter. I get it from Amazon. I do find it more reliable than using store-bought yogurt. Many people say that 3 to 4 generations of using your own yogurt as a starter is about as far as you should take it, but I’ve gone for months (lucky I guess) using the yogurt from a previous batch. Other times, it has failed me after a few weeks.

      I love that you are willing to try new things with your yogurt. It’s the best way to improve and customize your yogurt. Keep me informed about how it goes.

  11. I refresh my starter every 2 months by using fresh homemade butter. I normally make my yogurt using 5 litres of fresh milk (meaning directly from the cow) in 1 litre jars and when refreshing the starter I use 1/4 litre jar and add 1 tea spoon of melted (in room temp.) butter and for the rest of the milk I use my own yogurt. For the next batch I use the butter fermented yogurt. Fresh butter max of 5 days works very well and the bonus is the top of this yogurt to put on a fresh bread.

    1. Hi Gamze,
      How fortunate you are to have fresh milk. Your yogurt sounds fabulous. I love the idea of using the top of the yogurt to put on fresh bread. Thanks so much for sharing.

  12. I just made a batch of slimy yogurt. I am disappointed but this article really helps. Thank you! I did some searching and it was also mentioned that using 1% milk may contribute to the slimy texture which is what I used this time. Any thoughts on this possibility? I also like your recommendation to freeze portions of it to use in baking since I don’t want to eat it as is. I have been using your recipe for pizza dough in the bread machine and I am looking forward to trying many more of your recipes in the near future.

    1. Hi Jackie,

      So sorry about your yogurt. I feel your pain. I must disagree with the 1% milk as being the cause or even part of the cause. I have made hundreds of delicious batches of yogurt with non-fat, and 1% milk. True sliminess seems to happen when a few rogue yeasty bodies get carried away and cause an imbalance.

  13. I have been making homemade yogurt for years. I’ve experienced a slimy batch twice. Both times I used this slimy yogurt as the starter for the next batch, and both times the next batch was totally normal – no sliminess whatsoever. Go figure…

    1. Well…there you go. As one of my readers likes to say, “The yogurt gods can be fickle.” Obviously, we haven’t gotten to the bottom of this issue.

  14. Elias Herrera says:

    Curiousness enough I searched why is my yogurt stringy because I like it! I just finished making a batch by buying some yogurt that I once found had this texture and voila! Mine came stringy too! I like the texture and was looking how to make it again in case I would make more yogurt, I also don’t find any unpleasant aftertaste nor yeast flavor 😀

    1. Hey Elias,

      Interesting. My experience is that once you get a stringy batch, it’s easy to duplicate it. Guess you are in luck.

  15. What I did today with my slimy yogurt. It was a hit. Great to take on our hike.

    Banana Coconut Cranberry Oat trail biscuits

    1/2 cup melted coconut oil
    2 over-ripe bananas
    2 cups (slimy) yogurt
    2 eggs
    2 tsp vanilla
    1/2 tsp. salt
    2 cups rolled oat
    1 cup quick oats
    1 cup walnuts
    Several heaping handfuls of craisins

    Use cookie scoop to place on parchment lined cookie sheet. Bake (convection setting) 425°F about 20 minutes till golden brown on edges.

    1. Carey,

      These biscuits sound so delicious. I can’t wait to try them. Thanks so much for sharing your tasty solution for what to do with slimy yogurt since it’s safe to eat, but not necessarily a texture most people enjoy.

  16. Thank you, this was so helpful! I was trying to figure out what to do with my first stringy batch of yogurt, and pondering what was the cause, and this answered all the questions I had. You’ve saved me a lot of time going down rabbit holes trying to figure out all the possible causes!

    I usually use Green Valley Organics as my starter yogurt from the grocery store (it has 11 different strains of live active cultures, and is lactose-free which is great for me, since I am lactose intolerant, and use lactose-free milk as well when making yogurt.) I’ve been making my yogurt this way for a couple years, buying new starter cartons from the store when I’ve waited too long to make a batch of new yogurt & can’t use the last batch as starter.

    After this new batch turned out stringy/snotty, I went back for a closer look at my starter carton, and there is a slight stringiness to some of the whey. The yogurt it made is much stringier! First time I’ve ever had this problem. After reading your post, I’m guessing it was just some stray yeast that found it’s way into this individual carton, maybe after the yogurt in the carton was already made. That might explain why the carton only has a slight hint of stringiness to some of the whey.

    Also, I did decide to taste the yogurts, which all smelled fine, and then was worrying what mistake that might have been. This post has set my mind more at ease. Thank you, again!

    1. I’m so glad this was helpful, Carey. Thanks for writing.

  17. Susan McMahon says:

    This may be a stupid question but I am confused. I have been making yogurt for a while now using your recipe for Greek yogurt ie 2 quarts of milk, and fancied trying to make Icelandic yogurt. My query is both recipes are the same. I strain my yogurt until thick so am I making Greek or Icelandic yogurt? Also when I take it out of the fridge to eat there is always a bit of milky liquid is this normal?

    1. Susan, Yes, the recipe is basically the same. I do use Icelandic yogurt as the starter for making Skyr. Honestly, I can’t tell that much difference even if I use Greek yogurt as a starter. Icelandic yogurt is a lot thicker because it’s strained longer. This is a quote from my post about Icelandic yogurt. “…it takes 4 cups of milk to make one cup of Skyr. Traditionally, Greek yogurt requires 2 cups of milk to make one cup of yogurt.”

      It is normal to see some milky liquid on top, especially if you have not whipped your yogurt after straining. When strained and whipped, yogurt will rarely separate.

  18. Veronique says:

    Thank you! Now I know why my yogurt came out with the consistency of Spiderman’s venom.

    1. Uh oh! That’s a pretty good description.

  19. Jennifer L. Kuzara says:

    This is so, so useful! I made several batches recently, and for the first time I added powdered milk to the regular milk. I’ve been making yogurt regularly for almost 15 years, and this is the first ropey batch I’ve had!

    The sad thing is that I made two quarts of yogurt and two quarts of creme fraiche, and they all have the problem, so I think it was from yeast in the environment. I have celiac so there’s no commercial yeast hanging around, but I’m sure plenty of wild yeasts.

    My question now is what to do with it? It’s fine for eating, but difficult and not super pleasant. I’m trying to think through some ways I can use it in an altered form. I was thinking perhaps it could be frozen by the cup and used in baking. I usually make cultured butter from some of the creme fraiche, but not sure if that will work with ropey creme fraiche??

    Let me know if you have any ideas!! I’m anxious not to waste anything (especially now with fewer guarantees of finding good dairy at the store!). Either way, thank you for an excellent (and reassuring) post!

    1. Hi Jennifer,
      Freeze portions to use in baking. I use it in making cookies, pie crust, biscuits, etc. It would also be good in smoothies. Maybe other readers will have ideas.

  20. Cora-Lynn says:

    Hi ! I’ve just had a failed batch of yogurt ! So I thought it was my starter so I got new starter and tried again , with the same failed batch . It failed again . I’m not sure why . But was wondering if I could try again with the same batch ?

    1. Does it still smell good? If so, I would try again. Have you checked to make sure your incubation temperature is in the 100-110˚F range?

      If you aren’t sure you want to try again, try simmering the milk until it separates or clabbers. Let it sit on the counter for about 10-15 minutes. Carefully dip the curds out of the whey and put them in a strainer. You have just made fresh ricotta cheese. You can read about more about it here.