The wonderful thing about milk kefir grains is their endurance. Even after pausing their activity to produce kefir you can revive milk kefir grains. There are many reasons why you would need to revive milk kefir grains. Perhaps they were in the fridge for month or two. Or perhaps they traveled by  mail. The steps to revive milk kefir grains vary depending on the condition of the kefir grains.



Revive milk kefir grains that were in the fridge or sent by mail

This is a step by step instruction how to revive milk kefir grains:


1st Step: Take them out of the liquid and rinse with lukewarm running water, preferably non-chlorinated.

2nd Step: Put them in a glass jar (Kefirko jar) and add just a bit of fresh milk. It is better to use small amount of milk because the grains are not active yet.

5 steps to revive milk kefir grains2

3rd Step: Cover with a clean cap – not to tight to allow gas from the fermentation process to escape and leave the grains in milk on room temperature. You can use Kefirko jar that allows slightly opened top lid. Check regularly if there is a sign of activity.

5 steps to revive milk kefir grains3

4th Step: Shake the jar after 24 hours and see if the milk thickens or it stayed liquid. Stir with swizzle stick or wooden spoon.

5 steps to revive milk kefir grains4

5th Step: Strain the fermented milk – use the plastic sieve or strainer lid on Kefirko jar. Rinse the grains with running water and put them  in fresh milk. If the milk over-fermented use a bit more milk this time.


Repeat steps 1-5 for two to ten days. The clear sign or reactivation of the grains is thickening of the milk. However, pay attention to the smell and looks of it. In case it smells funny after several days or looks strange,  find some fresh grains.

Furthermore if the grains send by mail are fresh you can revive milk kefir grains quite quickly and they can produce drinkable kefir within few days.

Freezed milk kefir grains

It is possible to freeze milk kefir grains. In case to revive milk kefir grains, you need to thaw them in the fridge, strain them and repeat the steps written above. Again, it is important to check if the milk thickens and continue to change milk every 24 hours until grains can produce drinkable kefir.

Dried kefir grains

On the other hand, in case you have dried kefir grains the first thing you need to do is to put them in cold clean water for several hours to re-hydrate. After they’re re-hydrated, put them in the milk. From there the process is the same like with grains in other conditions – allow it to ferment at the room temperature for 24 hours and check if there are signs of kefir production.

Pay attention! If the grains are yellow, brown and crumbly don’t revive them but throw them away.


    • Hi!
      I’m not sure I understand. The grains were frozen or not? If the kefir grains are frozen they can last up to few months. You just take them out, thaw them and revive them (5 steps to revive kefir grains). If they were in the fridge, it’s possible they died. Try to revive them with milk and you will see if the fermentation will happen (the milk will thicken).
      Hope it goes well.

    • Hi,
      yes it can be harmful to put them in the water, especially if it’s not clear. Note, this is a revival of kefir grains. When you have activated grains there is no need to rinse them in water between batches.

  • I received milk kefir grains in the mail 3 days ago.
    I have been soaking them in milk on the counter since.
    The grains are floating on the top. Is that good or bad?

    • Hi Rita!
      It is possible to take more time for grains to activate. Does the milk thicken at all? Try changing the milk a few more days, maybe even stir the milk occasionally and leave it on room temperature. If the grains don’t activate in 7-14 days there is a possibility they are bad.

    • It’s fine. The grains are producing carbon dioxide gas, and that will often cause some grains to float. It’s perfectly natural.

  • Hi I was making Kefir regularly. Over summer I needed to take a break and I put them into milk and left them in the fridge for 2 months. Will they be ok the start up again ?

    • Hi Debbie!
      It’s hard to tell if your grains will still be active. Try to leave them on the room temperature and change the milk every day. The activation can last up to two weeks. If it thickens and the smell is OK, the grains are activated.
      Hope this helps!
      Best regards,

  • Hello, Kefirko.

    I was given a piece of kefir (as big as a walnut) about 6 years ago and always exspected it to increase in size.
    On the contrary it fell apart in many small grains and turned from white to brownish. It still generated good kefir, except for a few times with organically produced milk, which I had bought at organic food shops.
    Each time I used that kind of milk the result was a white, spongy, rubber-like lump of cheese swimming on top of the whey. The grains were enclosed in that cheese-like matter. It was hardly possible to re-extract them. Thus I lost almost my whole amount of grains.

    Inexplicably that did not happen when I employed organically produced milk of lesser (EU-Bio) quality.

    My questions are:

    (How) can I increase the amount of kefir-grains?

    What is wrong with organically produced ( Demeter, Naturland, etc.) milk?

    Thank you for your answer.

    Regards, Carsten

    • Hi Carsten!
      Thanks for writing. You are opening some interesting questions to which, I hope, our other readers and fellow kefir makers will also have some answers.
      It’s hard to tell about the quality of your grains without analysing it in a lab. Since they’re making kefir, which you find OK, they must be good. But it it natural for grains to grow a bit with every batch you make.
      What you describe with making it with organic milk, to me seems like over-fermentation. For how long do you ferment kefir? Separating whey from thicker kefir happens when you leave it to ferment for more than 24 hours, especially if the temperature is higher.
      So, there are a lot of things that can affect your kefir making. If you are out of grains, you can check if there is anyone sharing them on or you can get them here

      Hope all turns out well!

      Best regards,

  • Hi Kefirko,
    I was given kefir grains which I feed with Sucannet and just leave in the fridge. But then the past six months I didn’t feed it and it turned brown. I tasted it and it tasted like alcohol.
    Can I still revive it? I just wanted plain kefir with the milk.

    • Hi Marian!

      Thanks for leaving the comment. It’s hard to tell what is the situation with the grains. Six months is quite long period for live culture to survive without food. I would suggest taking it out of the fridge and pour fresh milk over them (just to cover them or a bit more). Then change the milk every day. This can take up to 10-14 days. If the fermentation process starts you will find the milk thickening and the regular smell of kefir … if the milk doesn’t change, the grains aren’t alive probably.
      Hope for the best!

      Regards, Urška

    • Milk kefir grains don’t feed on Sucannet, they feed on lactose. That is only in milk.
      You can use Duccsnet on WATER kefir grains. Two completely different srains.

  • Dear Urška
    I left my kefir grains in the fridge for about 3 weeks. I’ve been changing the milk every day, but no luck in getting the milk to thicken just yet.
    Could I revive them by placing a spoon full of healthy grains from my friend’s batch?

    • Hi Sue!

      Thanks for getting in touch! If I understand correctly, you are now trying to revive them after leaving them in the fridge for 3 weeks.
      – Did you change the milk, when they were in the fridge? You should change it approx. once a week to ensure they have enough food even when they are “resting” in the fridge.
      – For how long are you trying to revive them now? It sometimes takes up to 14 days for grains to activate again.
      – Do you revive them on the room temperature? If they are in the fridge, the fermentation slows down.
      – Other grains won’t significantly affect the old ones. If you have other activated grains, you should just use them separately.
      Hope this helps.

  • a friend gave me frozen milk kefir grains. I’m thawing in fridge. I have raw goat’s milk that I’m going to revive these with, Can I use cow milk kefir grains to make raw goat milk kefir?

    • Hi Martha!
      Thanks for your question. It’s possible to make kefir with goat milk. But since they were made with cow milk until now I would recommend to start with cow milk until the grains are revived. Then switch to goat milk and maybe leave some grains aside, if this isn’t success. The revitalisation period of grains is sometimes a delicate thing. Also when someone gives us the grains it’s best to slowly adapt them to different milk that we use.
      Hope it works out!
      Best, Urška

  • Hi,
    To slow down kefir production I leave the new batch (grains & fresh milk) in the fridge for the 1st 12-24hrs then transfer the jar to room temp, on the counter, for the next 12-24hr cycle.

    In this manner I produce a fresh batch every 2 days rather than daily. It has been observed that once they are transferred out of the fridge they are very active.

    Is this process harming the kefir grains?

    What is the ideal ratio of grains to 1lt milk (1 qrt). (Tbsp grains per quart?)

    Thank you for a gr8 site.


    • Hi George!
      Thanks for leaving a comment here. Putting grains in the fridge is slowing them down a bit. I do that every now and then when I’m away for a day.
      If you notice that the grains are more active after you take them out of the fridge, that probably wont harm them. You will see after a month or two if there are any changes.
      About the ratio, using Kefirko we fill up the small cup on the top lid for 0,6 l of milk kefir. That would be about a tbsp of kefir grains. For 1 litre that would be a bit more than 1 tbsp. You should try what is the right ratio because the results depend on the room temperature, milk and quality of grains too.
      Hope this helps.
      Best regards,

  • Hi, My mother-in-law found a kit for making Kefir maybe from the 80’s, is it even worth trying start them up? The little pack rattles like what ever is inside is completely dry.

    • Hi Lainie!
      That’s amazing. Try them out, maybe they will activate. 🙂 Put them in a little milk and change it every day. Be careful, do not consume anything if the look or smell of it is a bit off. This is probably a far-fetched experiment, but you never know. 🙂
      Best regards,

  • Hello I am new at legit making and I rinsed it with tap water…I forgot…did i kill it? Is there something to do…it doesn’t thicken the milk since 18 hours….it usually works after just two hours…I can see it start….now milk is liquid kefir is floating…but nothing else…I am so sad I assassinated my little guys.

    • Hi Tanya!
      It’s hard to believe you killed the grains just by rinsing them once. It’s true that water slows the kefir grains, so leave them a bit longer, maybe the milk will start to thicken anyways.

      Best regards, Urška

  • Hi, I’m Michael, I have one question. I’ve made kefir milk with sour smell and taste. one day, I thought kefir milk was over-fermented and washed my kefir grains with small amount of cold water( as same height as kefir grains or less within 5 secs), and fresh milk to reduce sour smell. After that, however, rate of fermentation was reduced and smell was not sour(but kefir grains are still like jelly and milk was thicken enough). I don’t know what’s going on and want to make taste of kefir milk sour again. please let me know how to resolve this problem.

    • Hi Michael,
      maybe you need to make more batches before the grains come to its previous potency. Sometimes washing them reduces their activity for a while.
      Let us know how it goes.

  • I received my Kefir yesterday. I strained them and put them in 3 cups of milk in a glass jar with the lid on and put it on the kitchen counter. I think it was a lot of milk. I don’t see anything happening after 15hrs. It just looks like regular milk no real change. Is there something I should be doing for it now. One thing though it was quite cool in my house.

    • Hi Alva,
      how many times have you repeated this process? You have to change the milk every day. This can take even up to 14 days, until the milk thickens, becomes kefir. Maybe you can use less milk, so you don’t make as much waste.
      Regards, Urška

  • I’m in a little disbelief. I have neglected my grains for approx 6 months – just at back of fridge and not fed at all. I believed them to be dead as there was also a pinkish mould and the time and neglect. Regardless of my thoughts I decided to see if there were any living ones (purely out of curiousity and HOPE!). I’ve given them small quantities of fresh biodynamic milk for the last two days and it seems they are active!!!! I’ll continue doing it for awhile so I can sift out any dead ones and strengthen them. I’m in amazement that they are still alive!!!
    What are your thoughts on this?

    • Hi Shelley,
      it’s interesting news.:)
      The kefir grains are a live culture and it seems yours didn’t die yet. If the kefir has the right consistency and smell they probably are alive. It is questionable what is the bacteria strains value in the kefir that you will be able to produce from these grains. Usually if the grains do not receive food they slowly die.
      Keep us informed how it goes.
      Best, Urška

  • Hi,

    So, I decided to visit my gf and to take my kefir with me, which was already fermenting for about 16 hours. I then left my car and took all my belongings but forgot my kefir. It was sitting in the car for about 3 hours on a hot summer day. When I realized it, i ran back and got the jar out of the car as quickly as possible. My question is: Is the kefir still safe to drink? Did I just kill my Kefir. It still looks find, but it was pretty hot when I got it out of there.

    Thank you!!

    • Hi!
      Thanks for leaving a comment.
      High temperatures make the grains “work” even faster, if your kefir was left in extreme temperatures it’s possible it’s not good to consume anymore. If you find it smelling funny or weird in taste definitely don’t drink it. The grains should probably be still OK, just change the milk and they would probably work ok since this happened only once.
      Hope this helps. Enjoy fermenting!

  • Hi Kefirko,
    I have used my kefir with expired milk. Only expired a few days, not more then 5 days. 2 of the bottles wasn’t open at all but when I opened it had a strong smell. I used organic milk. I used it to make kefir. My question: Is it safe to drink the kefir? Looked like the milk was thickening and fermenting but never used expired milk before so I am a little concerned.

    • Hi there, thanks for leaving the comment here.
      It’s hard to say for sure for your individual case if the drink is ok. You should rely on your taste buds and gut feeling. If you feel that the kefir is OK, maybe try it just a little and see for yourself if it’s ok. If the smell or taste of the kefir is off, definitely discharge it and make a new batch. 🙂 Regards, Urška

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