Water Kefir: Grain Multiplication and Carbonation – What to Expect


Previously in this series:


My first experience with kefir was in making milk kefir. I remember finally acquiring a taste for that tangy cultured milk and then promptly trying to figure out what to do with all of those grains. I also worked on the perfect culturing time and conditions to avoid the “carbonated” milk taste that I wasn’t too fond of.

After that I branched out into water kefir. I expected a similar culturing experience given that they share the same name and a similar microorganism profile. But since water kefir is a different cultured product, it was fitting that the process and the expectations should also be different.

Which is why I thought addressing the expectations for two big parts of the water kefir culturing process would be helpful. What should you expect for grain multiplication and carbonation when it comes to water kefir?

Grain Multiplication

When I first dabbled in water kefir I found that my water kefir grains made delicious water kefir, but never multiplied with as much vigor as the milk kefir grains did.

I thought I was doing something wrong. I thought I needed to feed them more often. I tried adding everything from egg shells to minerals to molasses. Still, they just didn’t multiply very rapidly; sometimes not at all.

But they were still making good water kefir. Eventually I learned that sometimes water kefir grains don’t multiply. Sometimes you can do everything right and use them for years, as CFH Customer Support Representative Bonni relayed to me in her experience, and still they won’t necessarily multiply.

They might, but then again they might not. That doesn’t mean that there is something wrong with them or that they aren’t doing their job. That’s just the nature of the grains.



Unlike milk kefir, I was actually really excited to get some carbonation from my water kefir. So when I started brewing it and noticed some tiny bubbles moving upward from the grains at the bottom of the jar, I got very excited.

But after the first fermentation I didn’t notice any notable fizz to the drink. Sometimes it would be slightly carbonated as I poured the cultured water kefir into new containers, and other times there was no carbonation at all. Then I found out that this was normal.

I also soon found out that the real fizz almost always comes from a second fermentation done in an airtight bottle like a grolsch bottle. During this second fermentation the carbon dioxide given off during fermentation is trapped in the airtight bottle and carbonates the drink.

This can be dangerous, though. If there are any cracks in the bottle, it could cause it to explode. The same goes for using any vessel not meant for bottling carbonated beverages. Just as a jar of pickles left un”burped” may explode, so can a jar of fermenting water kefir. So do take care.Once my expectations and understanding were realigned, I found that getting into a regular rhythm of making water kefir was not only a breeze, but also really tasty and energizing.

What are your experiences with water kefir grain multiplication and carbonation?


Shannon is a mama to four small children, homesteader, freelance writer, and picture-taker. She lives with her husband on their off-grid homestead where they make and eat kefir, kombucha, sourdough, and fermented vegetables.

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  1. gail says

    Great article… answered ALL my questions. My grains *seem* to be multiplying because I’m seeing smaller grains emerge–hopefully it’s not just the larger grains breaking down. I’m loving the lemonade made on the 2nd ferment and hoping that the ferment cycle is ongoing and taking care of even more of the sugar. Wondering how long you can keep the kefir made on the 2nd ferment. I mostly do my second ferment in mason jars so I don’t get a lot of carbonation, but I do have several of the grolsh type bottles and worry about how long before I need to worry about them bursting. I do pop the lids on them occasionally the first couple of days to left off some of the gas.

  2. Janelle Bensinger says

    My grains are multiplying like mad. From the one starter package I began fermenting in mid-Sept I have given away two batches (1/4 c for 1 qt) and currently have 5 qts fermenting!
    Honestly, I don’t want any more. I will be giving away two of these in the next couple weeks when the receiver is prepared for them but I hope they stop now. It’s more than we can drink or give away!! I wonder is there a way to dis-courage their multiplication?

  3. Brenda says

    can you do a 2nd ferment with nothing added? After 48 hrs my water kefir 1st ferment is still more sweet than I like so maybe fermenting it longer will be ok without adding juice? What are your thoughts?

  4. Mary says

    I have just started making water kefir, starting my 3rd batch :-) I have not been able to get any carbonation during a second fermentation period. I am using my canning jars and lids tightened down but no bubbles. Although I like lemon juice and water kefir without bubbles (makes the best lemonade) I would like to try it and others carbonated.
    Help… do I need other bottles for this? If I use the type of bottles, stated in the articles, how do you get the pieces of fruit out?
    Thank you.

    • says

      Mary – I have had mixed results when using canning jars for a second fermentation. Much depends on the lid and how tightly the lid and ring fit to the jar itself. That said, it often takes time to get an established water kefir culture up and running vigorously. You might try adding some extra minerals or sugar to your water to keep the grains happy and vigorous. Also, let’s troubleshoot the flavor of the water kefir after the first fermentation. Is it still pretty sweet or has it taken on a good tang? This can impact how much sugar is available for creating carbonation during the second fermentation.


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