How to Second Ferment Kefir

Many years ago I discovered a way to make kefir not only taste better, but to increase the nutrients in it. It is the only way that I make my kefir now because it is so delicious.  The process is called second fermenting. I have to admit that the reason I second fermented my kefir, is because it tasted so much better.

Nutrients and the vitamins will sky rocket!

Second fermented kefir will have more nutrients and the vitamins will sky rocket! This is due to the added prebiotics in the fruit or vegetables. When you add a new fuel source for the new microbes in kefir, they begin to grow and multiply, which increases all the vitamins and especially the folic acid, but it is the taste that makes me do it again and again. It takes away the super sharp sourness and mellows out the flavors. Everybody I have taught to second ferment has continued to do so because it tastes so superior to regular kefir. If you second ferment with a lemon or orange peel or a million other things it will flavor the kefir and make it taste unique and delicious. It also increases B vitamins, like folic acid, and makes the calcium and magnesium more bioavailable which means that your body can take it in and use it immediately. Basically, it is predigested and loaded with enzymes.

Second Fermenting

  1. Make your kefir using the basic technique, removing the grains afterwards.
  2. Place the kefir in a jar with a lid.
  3. Take the prebiotic item you want to ferment with, (choose from items below or experiment) and place in your jar with your kefir. Remember less is more. Too much fruit can cause your kefir to separate and taste bitter. One small peel of lemon or one slice of fruit is plenty for your jar. You can serve and eat it with extra fruit once it’s done second fermenting.
  4. Leave the jar on your counter for 1 to 4 hours or (up to a 1/2 day), then place the kefir in refrigerator and eat and enjoy. If the kefir separates into whey a little this is fine, and you can then place it in the fridge. If you want less separation than only ferment for an hour or two and then place it in the fridge and let it slowly ferment longer.
  5. I leave the fruit in the jar and just keep adding kefir to it until it starts to get soft and begins to fall apart, then I will add fresh fruit and 2nd ferment again.

This kefir, flavored with lemon or orange, is so yummy.  It is lighter and creamier than kefir made with the basic recipe and has a little more carbonation.  The taste is worth the extra fermenting and the nutrients sky rocket.

A lot of people I know will ferment kefir for long periods, leaving their grains in the kefir for days. Although this is not a bad thing, it makes for super sour kefir and can diminish the probiotics. As the microbes run out of food they can die, so longer is not always better unless you’re giving them another food source, as second fermenting accomplishes.

There are lots of ways to second ferment your kefir.


Just adding one or two strawberry to a quart of kefir will make your kefir taste so good!

Oranges or Clementines

One 6” strip of orange peel or one small circular slice of a fresh orange is plenty to flavor a quart of kefir. Don’t add more as it can make your kefir separate into whey and curds.

Chai tea bag

Adding one chai tea bag to a pint or quart of kefir will give you lots of different spices that flavor your kefir giving it a flavor you will love!

Dates and Vanilla

1-2 dates for a quart of kefir and a teaspoon of vanilla will make your kefir have a comforting flavor similar to vanilla bean yogurt.

Lemon peel

One 6” strip of lemon peel or one small circular slice of a fresh lemon is plenty to flavor a quart of kefir. Don’t add more as it can make your kefir separate into whey and curds. Lemon is one of the flavors I use the most.

Garlic cloves

2 peeled garlic cloves to a quart of kefir will give your kefir a savory taste. I love to use this in dips and salad dressings. Check out my recipe page for recipes.
468 Responses to "How to Second Ferment Kefir"
  1. Donna! Thank you so much for all these wonderful resources and recipes! Your book has totally inspired me and now I’m telling all my friends and patients to get get your book or come to your website to learn how easy it is make their own kefir at home.

    Is there a rule of thumb for how much fruit to add? Will dried fruits, like mango, work too?

  2. I’m so happy to have found your site. I had no idea about second fermenting having even more nutrition. My question is that if the kefir needs sugar from fruits to eat for the second ferment, then how can a tea bag or spices work without fruit or peels added?

  3. I want to make vanilla kefir cheese and use it as a fruit dip. Would you recommend a second ferment? If so how would you do that?

  4. After 24 hrs fermentation, I refrigerated my coconut yogurt. The next morning I tasted it and it is not sour at all. Can I re-ferment my yogurt. I had them in the oven with the light on. If so, how can I do this properly. PS- I used Kifer Starter rather than grains.

  5. First off, I love the ideas on this website!!! I am looking forward to trying the flavored 2nd ferment. However, I will also say that flavoring for a 2nd ferment is not necessarily needed. I have done lots of 2nd ferments without adding anything. We are on GAPS Diet and also do a very long 1st ferment. And we actually LIKE the zingy, sour taste, including my 9 year old daughter.

  6. Is it essential to add fruit for a 2nd ferment? What are the benefits and/or drawbacks of doing a 2nd ferment with just the kefir as is? Thanks – Locke

  7. I am trying the second fermentation… do I leave the fruit or flavor source in the whole time or do I remove it when I go to refrigerate. Thanks!

  8. Thanks a lot for this information. I am trying the second fermentation at this moment. I am trying some raw cacao nibs. Do you think this works?

    Do you have any idea how much B vitamines are in 100 ml. kefir after the second fermentation?

    One last question, after the kefir is ready I use it to put my oads in over night. I do this in a pain (stainless steel). I know the grains should not be put in this, but how about the drink without the grains?

    • Raw Cacao nibs are great!

      I do not know exactly as it depends on the milk you use.

      Yes you can add the kefir without the grains overnight to oats.Works great!

  9. If I made a jar of kefir and accidentally spilled the grains. I have stored the strained kefir in the fridge for the past week. Is it possible for me to get “new” grains from the stored kefir and if so how do i go about it? Please help

  10. I had been neglecting my grains in the back of the fridge for a few months (in whole cow’s milk). I pulled them out a few days ago, rinsed them, and put them in fresh 2% cow’s milk in their jar. There were a lot of them since it included all of my backup cultures. The kefir separated, so I tried mixing it up and second fermenting it with a vanilla bean. It became very fizzy (not my preference) and extremely sour. I threw it out and started a second batch, which was very thin and sour. Are my grains irreparably damaged from being in the fridge so long? Or do they just need more cycles to get back up to speed?


      • While I don’t know the science behind it and can’t confirm how healthy it is, I have stored my kefir for months at a time and they always come back. The first several batches taste off and then after a few days of nice room temperatures, they are back to making thick delicious kefir.

        I do use raw milk. I’m not sure if that makes a difference. Just wanted to share because I’m glad I didn’t get rid of mine.

    • I just revived my grains after 6 weeks in the refrigerator w no new food. I started them in about 3/4 c. milk and changed it twice a day, I went thru 1/2 gallon but they are active now.

      • You might want to try a regular size batch instead of 3/4 cup milk. I believe that to be a waste as it doesn’t give the grains much to eat. Giving them a full batch of 1 qt or half gallon of milk at one time will help them wake up faster and probably waste less milk. You can give the off tasting milk to pets or chickens. I’ve done that.

  11. I add a cup of store-bought Kefir to a quart of milk and let it ferment for 18 to 24 hours. The result is thicker and more creamy than the original kefir and has a much milder taste.

    After doing this a few times I saw an article that said you could not make kefir using the process I use. If that’s the case and I shouldn’t call it kefir then what is it.

  12. hi… just started making kefir and I live all the way in Kolkata India where it is hot. How long should I leave kefir out when its like 30 deg cent. ? Also i tried to second ferment and added some fresh milk and honey. Is that ok?

  13. Hi, if my kefir has already separated into curds and whey, is it still possible to 2nd ferment it?

    Thank you!

  14. I like to put a little raw honey in my second ferment. Should i wait until its done? Thank you, BTW, I was struggling with the lactose and thought 2f and ripening were the same. I absolutely adore and crave my delish kefir now!!!

  15. I’m making a 3-day supply of goat’s milk kefir for my son. He likes sweetness so I’m thinking of adding honey, banana and ground flax seed to a smoothie before taking it to him. Is it okay to use honey? Thanks

  16. Dear Donna, my son is five weeks old and is bothered by severe cramps. He is in pain and it’s frustrating to see him suffer. Our physician has told us this is normal in small babies, it can last up to three months and to “wait for it to pass”. He is breastfed exclusively. Is it enough for me to start drinking kefir, or should I give it to him directly in order for him to benefit from its healing properties? If so, how much kefir should I give him?

    • Jennifer–I have 5 kids and I’ve had this problem with each of them. Nothing seemed to get better until I removed dairy from my diet. Upon reading this from Dr. Sears, it now makes sense. “The colic-cow’s milk connection. New research supports what old wives tales have long suspected: some breastfed babies become colicky if their mothers drink cow’s milk. That’s because potentially allergenic protein called beta-lactoglobulin in cow’s milk is transferred to baby through the breastmilk. This allergen upsets the intestines [just] as if the baby had directly ingested the cow’s milk.” here’s the link:

      Now, with that said, a quick google search ( and it appears that the beta-lactoglobulin is NOT broken down during the kefir-making process, so YMMV. It might be worth taking ALL dairy out of your diet until he’s 6 months and concurrently giving him some Jarrow’s probiotic powder (either placed on your nipple, or pumping and putting it in his breast milk) to help his gut heal. I’m no kefir expert, but I do have a lot of experience with gassy, crampy, babies in pain. It totally stinks to have to watch them be so uncomfortable! When I removed milk & ice cream from my diet, things got better immediately. I think yogurt or kefir for YOU may be ok, but it’s trial and error. An elimination diet can take up to 6 weeks, so hang in there!

    • When my daughter had “colic” someone recommended taking her to a chiropractor. After 2 weeks of us both suffering, I broke down and tried it. Her colic was gone that day. Sometimes in the “trauma” of birth, the neck can get out of alignment and causes severe nausea. A simple finger tip adjustment can clear it up.

    • Hi Donna,

      My son had what they called “colic” for several months. We were eating processed, chemical laden foods and I had never heard of kefir. He would have so-called 104-105 fevers, major gut pain, unexplained rashes among other problems. Later, he would get night terrors, rashes, very bad temper tantrums and became in his own little world. The doctor said all these were unexplained. But when I put 2 and 2 together, it matched up perfectly with his vaccines. He was having adverse reactions with all his symptoms. None of these were ever reported to VAERS. After he got 8 vaccines in 1 day at 14 months old, he changed forever. He became ADHD, which is part of the autism spectrum. Please do your homework before allowing anything to be injected.

  17. Thank you for such great information! I love second fermenting with cinnamon and vanilla extract on top, but was wondering if the alcohol in the extract kills any of the good bacteria?

  18. Hi if I have cold milk kiefer already made in fridge can I add oranges then put back in fridge or leave out? Mine is too sour and I need it to be more pleasurable to drink. Thanks

  19. A friend just shared some of her grains and gave me a crash course in kefir making. She uses a coffee filter secured by a rubber band on top of her jar, so I did the same although I had purchased plastic lids (where did I read that?) so what’s the deal with clamp down lids? As she demonstrated, she stained out the grains, putting the liquid into her blender. She used 100% orange juice to create her finished drink. I used strawberries in my blend. When I went to use it the day after, my drink had seperated, cloudy liquid on the bottom. I just shook it and drank..not as sweet as I thought, but not terribly sour 🙂

  20. Do you have to use fruit or flavoring on the 2nd ferment or is it OK to just leave the strained plain Kefir by itself on the counter for 4-12 hours? Just got my grains this week and am ready to try the 2nd ferment to see if it will get to be a thicker consistency.

      • Thanks Donna, I did the 2nd ferment last night for 11 hours using lemon peel and in hopes that the kefir would thicken a bit but It stayed at milk consistency. We aren’t real fans of flavored kefir. Is there anything I can do on the first ferment to make it thicker/creamier? I am using 2% milk, room temp 68˚, the grains are doubling every 24 hours, taste is pleasant…its just thin like the 2% milk I put in.

  21. I’m on my way!
    Just found out about Kefir, been in hospital for some time now having had bowel cancer removed & bladder patched up where bowel came into contact with it.
    Been sent home with a clean bill of health, but feel lousy have to do potty training again @ age 76, its a struggle, but I am determined to improve!
    This is where Kefir comes in (I hope), had my first taste this morning—fingers crossed.

  22. Hi Donna, like everyone here I’m over-the-moon happy with your fermentation ideas and no-fail information. One question for you that I couldn’t find information on in your book: when cheese forms what is the best way to fish out the grains? I find that I don’t always get them all. Is there an easier way as to not disturb the cheese? Thanks so much.

  23. When I second ferment, should I always clamp it down so no air gets in or is there anytime where I would second ferment on the counter and just use a coffee liner on the top of the mason jar?

    • Also, can I use any fruit for my second ferment on the counter? I’ve been using banana, seemingly going ok, but recently when I use banana in my second ferment….once I put it in the fridge, it becomes super super carbonated. I’m afraid I’m spoiling the kefir milk by putting banana in it on the counter for second ferment. Any comments or suggestions? Thanks!

      • Yes, you can use any fruit but bananas have a lot of sugar so only use a small amount and only let it ferment for an hour on the counter or let it ferment in the fridge.

        • Thank you for that information…haha…I have super carbonation, I’ve been putting a whole banana in a 1 quart mason jar and letting it second ferment for 12 hours. A couple of those round mason lids have actually bent in the fridge from the kefir trying to push it’s way out. I’m going to have to “back her down”… 🙂 Thank you!

  24. I recently bought dehydrated kefir and am not sure what is going on. I am on day three and the milk is still thin. Also I can’t really tell the difference between the kurds and whey, and grains, it is all very thin. I also left the milk out to second ferment, but it has turned to kurds and whey and water. Was it too soon for a second fermentaion?

    • Sometimes it takes longer becuase they are dehydrated. Cultures for health has a live chat and they are the manufactors and they can help you more if you need it.

  25. I’m waiting to purchase kefir grains until I return from a 6 week trip. In the meantime, I’m using your powdered culture packets and having fun with those. I assume I can second ferment these batches, too, by just putting the ‘goodies’ in the jar and adding a regular lid?? I’m planning to try apples and chai tea.

  26. Hi Donna, So if wanted to do the second fermentation to use in the kefir onion dip you have listed and I wanted to do garlic, do I still use the lemon or orange or just some garlic cloves? Thanks! Love your recipes and I recommend your book ALL the time!

  27. This may be a silly question but after second fermenting, e.g. with orange peel, do you remove the peel before refrigerating?

  28. I am so excited to try the second fermenting.I love both lemon and orange so I planto try the lemon and fresh raspberries tomorrow. Thanks so much.This is so much fun.

  29. I flavored a batch of kefir the other day by whizzing it in the blender with some blueberry’s, then placing it in a jar in the fridge for later use. If you have ever done this, you can guess what happened next! The whole thing congealed into what I would call a think pudding, almost a cheese. I put it in a cheese cloth to strain a bit more, drizzled it with honey and served it with crackers. It turned out to be a pleasant mistake that I will most likely repeat!

  30. Hi Donna ~

    I just wanted to clarify, do you keep the grains with the 2nd ferment? I am excited to try! Your kefir looks so smooth & creamy ~ I’m only in my 1st week but seems the results continue to improve with each day. Hope to be an old hand at it someday 😉

    Thanks ~ Kendra 🙂

  31. Hi Donna, after you’ve made a batch of water kefir and removed the grains, do you store the grains on the counter in sugar water or in the fridge?

  32. I love your book! What a great resource! I am wondering when it is no longer safe to drink the second fermented kefir. I am trying out my first batch and I accidentally left it not 4-24 hrs, but just over 48 hrs. And I’m sure this won’t be the last time. It is super bubbly and tastes a sour, but not bad or foul. The whey had separated to the bottom and the it curdled on top. Think it’s still safe?

    • Here’s my secret: The sour part is just on the top layer that got exposed to air.
      If you absorb it by laying a paper towel on the surface, and throwing away that liquid once or twice (use a spoon if dry), the kefir below is still yummy!

      I always discard the whey because I love it creamy 🙂

      If the milk was close to expire (In Chile they print a number in the base of the carton, stating how many times that milk went back to be pasteurized, and it goes up to 5!) or there were not enough grains to cover the surface once they float…, or the temperature was kind of cool… or you poured cold milk on the warm grains…or you just took them out the fridge from a long hibernation… all factors that could make the kefir SLOW, the milk could have been gone bad before the kefir actually grew from it.

  33. oh and can i simply add frozen berries or fresh/frozen apples for 2nd ferment? or only fresh citrus fruits like orange will work? tx once again!

  34. hi, i read that milk kefir grains love cream the most… can i use melted ice cream as the base for the first ferment? will this make them fat and healthy or kill them?

    • I have never done this but you can try it. Kefir loves the lactose in milk and not necessary the cream. Its funny people say all kinds of things but kefir loves all kinds of milk and minerals too especially lactose.

  35. I’ve been using my own Nubian goats’ milk to make kefir with grains. A friend shared a small amount of grains to get me started. My grains love my goats milk and are multiplying like rabbits! I ‘m just thrilled to have your information so readily available. I am trying second fermenting for the first time with my own wild raspberries and strawberries. I didn’t remember to use a clamp down jar so I am going to put it in the fridge and try again. The color and smell are luscious. Thank you for teaching and inspiring me! I recommend you to everyone when I’m explaining about making kefir.

  36. I’ve had a couple of times that I’ve gotten distracted and forgotten to strain my kefir and it’s gotten super sour. I just mix it with my dog’s and chicken’s food and they get a wonderful treat. It doesn’t happen often, but life happens and even though I’m retired, I do get busy. I love your site and with each batch of grains that I share with my friends and everyone that I talk to that is making their own kefir, I suggest your site. I have your cookbook and love all the ideas for using my kefir. I’m a water and milk kefir brewer as well and kombucha and other fermented foods. My friends call me an old crone as I’m always brewing up something and I never leave my house without my snippers and a mesh bag to collect ‘weeds’ and plants on my walks to make into my wonderful concoctions. Thank you for all the wonderful information and for keeping up your site up to date.

    • For you and anyone who hates sour kefir and likes thicker creamier Kefir:

      If you move it to the fridge as soon as it starts to separate, (or before) and let it settle for a few days, you can have it thick, and REMOVE the sour/acid part EASILY. Just sit a paper towel on the surface before to strain it, let it soak in the top layer, and throw it away.

      I discovered the kefir gets better when the lid is made of paper towel or fabric (cleaner to dispose the paper). It must have to do with the alcohol / CO2 formed when there’s oxigen or not, like the wine. One makes alcohol for wine, the other makes the CO2 for the cider…
      So I thought that maybe only the top layer in contact with the oxigen is the one that becomes sour, and IT WORKED! If you remove it, the kefir below is tastier, but not sour.

      You should avoid to mix it or move it until after you removed that layer, and you can even pour the whey out, before stir it or strain it, if you like it thick like me 🙂

      My other secrets are:
      Never pouring cold milk while the grains are warmer.
      Keeping the kefir WITH the grains, undisturbed, until consupmtion. Also you always strain it in cold, so it’s easier to re-add milk without waiting, since both are cold.
      Since I keep the batch inside the same jar with the grains, I can store it for days without the grains thinning out (i.e. starving), have it fresh to drink, and they never get sick (if you pour cold milk in the warm grains, they’d make kefir very slow so your next batch would be just spoiled milk, or not as bubbly.

      Good luck.