Water Kefir Second Fermentation

Stronger flavour and extra fizz with a second ferment…

A second fermentation is a great way to produce more flavour and more fizz in your water kefir. At this point you will have strained the grains and the remaining liquid (water kefir) will still have bacteria and yeasts that will feed on the new sugar ( fruit, juice etc..) during the second ferment.

Just to be clear and to avoid any confusion, you can of course drink water kefir after the first ferment with no flavouring at all but to be fair it doesn’t taste so good at that point. If you want to drink it like that then maybe add it to your smoothy or add it to other drinks.

One of the most important things you need to know is that, after your first ferment (when you have water kefir ready to consume), you have two options:

  1. Add flavour and drink it right away.
  2. Add flavour and wait, this is called a second ferment (and usually produces more fizz and more flavour).

But why don’t I just add flavour during the first ferment?

  • You you can and we are not saying this is wrong BUT we much prefer the second ferment option because this will stop your water kefir grains from absorbing the flavourings (and colour) which is important as you can then go ahead and add a different flavour to the next batch you make.
  • We believe the second ferment option will keep your water kefir grains healthier as fermenting in some flavourings such as juices can be really hard on the grains.
  • The second ferment keeps your grains clean. Fruits usually break down whilst fermenting and the result is small bits of fruit that get mixed into your grains making it difficult to remove them.

So, we recommend you do the first ferment with no fruit, flavourings etc.. then use one of the flavouring methods with the second ferment.

1. Flavour right after first ferment ( without the second fermentation)

Extracts: Add 1-2 teaspoons of vanilla extract or similar, we like vanilla as it produces a cream soda flavour, you can add more or less to adjust to your liking.

Spices: Add spices such as ginger, dried lavender, cinamon sticks ete.. etc.. These will produce a lighter tasting water kefir when added to your drink. If you prefer a stronger flavour, you can add these and then move on to the second ferment.

Fruit / Berries: Add approx half a cup of fruit per 1litre, again this will produce a lighter tasting water kefir when added to your drink right away. If you prefer a stronger flavour, you can add these and then move on to the second ferment.

2. Stronger flavour and extra fizz with a second ferment…

The process:

  1. Go ahead and add one (or more) of the flavourings below to the cultured water kefir and seal the bottle. Be sure to leave 1″ – 2″ of headspace at the top of your bottle as pressure will build. NOTE: If you prefer not so much fizz then just cover the jar with a muslin cloth or similar and rubber band.
  2. Let the jar sit for 24-48hrs during the second fermentation.
  3. Check after 24 hrs to see if some fizz has built up inside the bottle, if not allow to ferment for an additional 24 hrs.
  4. Once satisfied with the taste, strain the liquid into a bottle, jug etc.. and place it in the refrigerator in order to chill before drinking.
  5. Now open the bottle and enjoy!

Flavourings that we like to add during the second fermentation:

Fresh fruit purees or juices:

This is one of our favourite way to flavour water kefir, and that’s because we like our water kefir well-carbonated and bursting with flavour. One of the key factors to allowing the yeasts access their food source (the sugar) is breaking down the fruit to be as easily digestible as possible for the yeasts. When you make a puree from fresh fruit, you’re actually breaking down the fruit molecules and therefore making it easy for the yeast to feed on the sugar once added to the water kefir.

You will usually find, when you you use fresh fruit purees and juice the water kefir will almost never turn out flat and will produce a lot of fizz. If you want consistent carbonation then we recommend using fresh fruit puree.


All berries work very well and to mix things up a little you can add a combination of different berries such as: strawberries, blueberries, cranberries, blackberries to list just a few… you could also try kiwi, peaches, cherries, etc..etc.. Just make sure to chop up the fruit before adding to your water kefir.

Ginger: 1-3 tsp. grated fresh ginger or a few slices. This is a really popular flavoring

Dried fruit: apples, papaya mango, pineapple and are all great choices.

Raisins: ¼ cup of raisins. We really like this one as it produces a slight Dr. Pepper taste. Give it a try!.

and of course fresh herbs: fresh lavender, mint, or lemon verbena all add a little flavour to the drink.

Your Ideas…

If you have any other ideas for flavourings, please feel free to send them through to us, we’re a friendly bunch and we always love to try some new combinations.


When fermenting more than one live culture at home, we suggest a distance of at least 4 feet between the cultures at all times. This is to help stop cross contamination of the different cultures and is of particular importance when culturing dairy products. The only exception to this is when cultures are being stored in the refrigerator with tight-fitting lids.