February 23, 2019

Which fruit juices work best with water kefir?

water kefir and fruit

Arguably, the best part of water kefir is doing a 2nd ferment with fruit juice. If you are yet to try it, you are definitely missing out. It creates a super fizzy, refreshing, tangy, semi-sweet, semi-alcoholic cocktail. It feels like a treat, but it can still be quite healthy in moderation.  

How to do a water kefir 2nd ferment with fruit juices


  1. Do the usual 1st ferment with water kefir grains and a sugar mixture.
  2. Strain water kefir grains from the finished kefir.
  3. Pour finished kefir into glass container with a lid. Swing top bottles work great for this as it will help build the carbonation.
  4. Pour 1/4 to 1/2 cup per quart of fruit juice of choice (raw is recommended) into the bottle with the kefir. If you are using a 16 oz swing top bottle, use 1/8th to 1/4 cup of juice.
  5. Close lid and let it set for 12 to 48 hours at room temperature. An alternative is let is sit in the fridge for 3-4 days. Be careful of too much carbonation as it can break the bottle! Burp the lid or jar every so often if you feel you need to.
  6. Drink fresh or chill in the fridge before consuming. Enjoy :)

As a word of caution, this is mostly for the adults as the alcohol level can sometimes rise above 2 or 3%. It’s probably one of the most enjoyable health drinks you can make, but like with all good things, enjoy with moderation.

A detailed study on water kefir 2nd ferments with fruit juices

A fascinating study recently came out testing 6 different Mediterranean fruit juices mixed with water kefir during a 2nd ferment.

They tested all sorts of different things like the alcohol level, carbonation, antioxidant ability, acidity and they even used a panel of people to judge the final taste of the water kefir fruit juice.  

They tested apple, grape, kiwifruit, pomegranate, prickly pear and quince juice.

Grape is always a favorite in this household, so it was really interesting to see how it stacked up against the others.

The results are fascinating and confirms mostly what we’ve experienced with our own testing.

Probiotic Count

Fascinatingly, the fermented prickly pear juice had the highest amount of bacteria and yeast. It’s interesting because the history of water kefir traces its origins to Mexico and the use of the prickly pear. It’s probably no coincidence that the bacteria and yeast thrive so well. The water kefir that fermented the prickly pear registered 8.4 log cfu/ml for the total count.  The other 5 fruit juices ranged from 7.4 (the kiwi) to 7.9 which was the grape and pomegranate.


The 3 highest fermented juices in alcohol content was grape, pomegranate and quince. In the study, all 3 of those fruit juices registered over 4% alcohol.  We always get a good kick when we do 2nd ferments with grape juice, so its not surprising that it registered as one of the highest.  If you are looking for a low alcohol producing fruit juice, try kiwi fruit. It was only about 1% alcohol. The prickly pear and the apple showed about 2.5% alcohol.


Antioxidants protect against aging and all sorts of diseases, so its always important to incorporate antioxidants into the diet whenever possible.

Out of the 6 fruit juices that were fermented, the pomegranate and kiwi fruit had the highest antioxidants. Prickly pear and quince and moderate levels of antioxidants. The lowest two fruit juices in terms of antioxidants was grape and apple.  The difference between the grape (which was the lowest) and pomegranate (which was the highest) was quite large. 15% vs 88% as measured by DPPH.

Pomegranate juice is know for its high levels of antioxidants so that makes sense. But grape was the lowest which was surprising as grapes and wines are known to have good antioxidant characteristics. One study showed that much of the antioxidant ability of grape reside in the skin depending on the type of grape. The study did not specific which grape was used, but that could be one of the factors involved.

Carbonation / fizz

The fermented pomegranate juice created the most carbonation by quite a significant margin. Quince, prickly pear, grape and apple had moderate carbonation and fizz. And the lowest was kiwifruit. When we have done fruit juice water kefir 2nd ferments, we have found that most fruit juices create plenty of carbonation no matter what fruit juice you use. Most of the time, too much carbonation is the issue as you don’t want jars exploding all over the counter or fridge.

Acidic content

The acidic content falls somewhat in line with bacteria and yeast activity.  The prickly pear produced the most lactic and acetic acids. This makes sense as it had the most bacteria and yeast.  The others were moderately lower. Apple had the lowest overall acid levels.  Grape had low lactic acid, but high acetic acid.


Perhaps the most important part of a fruit juice water kefir ferment is the flavor.

In the study they put together a panel of 15 people (9 men and 6 women) to see which flavor they preferred. Grape and Apple won out as the overall favorite for the taste testers. I can personally attest to that as grape and apple are one of our favorites as well in terms of flavor. Kiwifruit, prickly pear and pomegranate juice were in the middle. Way down at the bottom was the quince juice. Poor quince.


Summary highlights


Prickly pear

Prickly Pear Juice

  • Highest probiotic count
  • Highest acidic content
  • Average antioxidants
  • Average alcohol
  • Average taste
  • Average carbonation

Red apple

Apple Juice

  • Best taste
  • Average probiotic count
  • Average alcohol
  • Average carbonation
  • Low acidic content
  • Low antioxidants

red grapes

Grape Juice

  • Best Taste
  • High alcohol
  • Average probiotic count
  • Average carbonation
  • Average acidic content
  • Low antioxidants


Kiwifruit Juice

  • High antioxidants
  • Average taste
  • Average acidic content
  • Low probiotic count
  • Low alcohol
  • Low carbonation


Pomegranate Juice

  • High antioxidants
  • High alcohol
  • High carbonation
  • Average taste
  • Average probiotic count
  • Low acidic content


Quince Juice

  • High alcohol
  • Average antioxidants
  • Average probiotic count
  • Average acidic content
  • Average carbonation
  • Worst tasting

Bottom line

Doing water kefir 2nd ferments with fruit juices is a healthy fizzy treat. Caution is advised due to the higher alcohol content than your typical water kefir or other ferments.

If flavor is your ultimate goal, try doing a 2nd ferment with grape or apple.

If you want the most probiotics, try prickly pear.

Want good antioxidants, try pomegranate juice or kiwifruit juice.

Want the enough fizz to blow up the kitchen, try pomegranate juice.

If you want alcohol, try grape, pomegranate or quince.

It's up to you. One of the best parts of making kefir at home is that it is so much fun experimenting. You can even try it with ginger beer plant or kombucha!

Vegetable juice ferments are also another healthy way to make great kefir.

What's your favorite fruit juice to mix with water kefir?