Once you have made your way in kefir making process and figured all the right measures, sizes and tastes of it, it is a good time to consider doing a second fermentation of kefir. It may seem as extra work that is not really necessary, but it actually has quite some benefits. The main differences between two fermentations are that in the second fermentation there are no kefir grains, and it is done in a sealed jar.


During the process of second fermentation kefir changes in several ways. To name a few, its taste is not as sour, its texture is creamier, it increases levels of B vitamins in kefir, as well as the levels of magnesium, calcium and probiotics. On the other hand, the levels of lactose are reduced. This happens because bacteria use lactose as a food source. Moreover, people who are sensitive or intolerant to milk may enjoy the second ferment kefir without negative consequences.

There are several variations to second ferment kefir. For example, after first ferment, you need to remove grains from the kefir, bottle it and leave it in the fridge for a few days. Or you can make kefir directly in the fridge. However, the best effects will give making second ferment outside of fridge, without grains.


The first step is to harvest your kefir and remove all the grains.



The second step is to pour kefir in a jar with a lid. There shouldn’t be space for air to come in.




And in case you wish something more than plain kefir taste, the third step of second ferment is flavoring the kefir with fruit, spices, juices or herbs. This is perfectly safe to do as the additional flavors cannot affect kefir grains.

And the final step is to seal the jar tightly and leave it for around 6 to 48 hours. Again, the time of the fermentation depends on the temperature, as well as on your taste. It could be good to taste it from time to time and figure what works best.


9 comments on “How to second ferment kefir

  • Wow, great, my kefir is very ceamy too! I didn´t know that is becouse of second fermentation. When I remove the grains I put kefir in glass bottle and put it in the fridge. Sometimes I don´t drink it every day and than gets more creamy. I like it more like that. So it is a variety of use.

  • I still haven’t made milk kefir, although I’ve made water kefir many times. Is it the same, in that you have to make it daily? That’s the only thing that’s stopped me from making it, as I could see that getting expensive with milk.

    • Hi!
      First fermentation of kefir usually lasts about 24 hrs, when you strain it for second fermentation it is best to use the grains for the next batch of kefir. But you can easily store the grains in a bit of milk in a fridge – that will last a few days. Otherwise you can store the grains for a longer period in water (use non-chlorinated) also in fridge. By storing them in cold place you slow them down, so next time you will want to make kefir you will need a short activation time. You can read about making kefir in other posts on this blog. More content about revival of grains is also coming soon. Happy kefiring!

      • Can I use my milk grain to make Water keifer?? Or will water kill my milk grains? I would like to start making water keifer. Thanks.

        • Hi,
          thanks for an interesting question. It is possible to convert milk kefir grains to water kefir grains and there are some tips on the web how to successfully do so (search: convert milk kefir grains to milk kefir grains). But this usually takes some time and it is possible to kill the grains during this process, so make sure you keep some extra live grains aside. Otherwise it might be easier to search for someone nearby who already has some active water kefir grains, check out http://www.kefirhood.com – a new app that allows you to share and search for kefir grains. Enjoy making kefir! Urška

  • Hi just got a little confused fro m the statement below..excerpt from the top of this blog post

    Please clarify.Thanks

    However, the best effects will give making second ferment outside of fridge, without grains.

    • Hello!
      The author expressed his opinion that the best results from second fermentation comes when you leave kefir on the room temperature for a day or two.
      Fermentation always happens faster if you leave the kefir on the room temperature. This is also the reason we put the grains in the fridge for a few days when we want to take a break from making kefir. Lower temperature slows them down.
      Second fermentation happens when we already strain the grains from kefir. Even though the grains are not in the kefir anymore, the cultures remain in kefir. This is way the kefir gets more sour and tart after some time.
      Hope this answers your questions.
      Best regards,

  • Thanks Urska, That helps

    just wanted to know if the i am making kefir cheese using the kefirko cheese maker.

    1. Should i use the kefir from first fermentation or from second fermentation? Which is better?

    2. Can i keep the pour the kefir into the kefirko chesse maker and leave it outside at room temprature” or must it be kept in the fridge?

    3. If i purchase milk kefir grains from kefirko.com do i need to activate the grains?

    4. Do you folks sell water kefir grains?


    • Hi!
      I’m happy to answer your questions.
      1. You can use both. It depends on the taste you want. The one from the second fermentation is already a bit thicker and more sour and tart in taste.
      2. You can leave it outside but note that fermentation will be going on faster, the taste can change. We recommend putting it in the fridge so you slow down the second fermentation.
      3. Yes, you have to activate our grains, we send the instructions with the grains.
      4. Not yet, but it’s just the matter of days when we put it on our web shop. They’ll be dehydrated and will also need activation.

      Hope this answers your questions. Have a nice day!
      Best, Urška

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