What is Water Kefir?

Water Kefir Grains ( also known as Tibicos in Mexico, Japanese water crystals and California bees) are a SCOBY – a symbiotic colony of bacteria and yeasts, held together by a polysaccharide biofilm matrix created by the bacteria. The grains can maintain a stable culture by using carbohydrates ( ostensibly sugary liquids) to produce lactic acid, ethanol and CO2 which carbonates the drink. They seem to have had a have a much wider world distribution that milk kefir grains, which are known to originate from the Caucasus region. Water Kefir Grains have been used in Mexico for many years in the production of a fermented pineapple drink called tepache. Wikipedia says that the grains form on the pads of the Opuntia cactus (from Mexico) as hard granules that can be reconstituted in a sugar-water solution as propagating water kefir grains.

Water Kefir Grains are found all over the world and cutures are never exactly the same, but typically containing species from Lactobacillus, Streptococcus, Pediococcus and Leuconostoc bacteria and Saccharomyces, Candida and Kloeckera yeasts.  They are thought to be a relation of the ginger beer plant that some of us may remember from our youth.

See how to make water kefir.

You can also make coconut water kefir, which uses coconut water instead of tap water.


More detail and fine tuning the process – a series of Q and As

 What should it taste and look like?

Water kefir and coconut water kefir are both slightly cloudy fizzy watery liquids. They shouldn’t be at all thick or viscous. The taste is hard to describe – a bit soda-watery with a hint of bicarb, balanced by a touch of sweetness and a touch of whey comes to mind (though there is absolutely no animal product in this at all).

What sort of vessel is best for fermenting?

Water kefir fermentation makes a lot of CO2, which we need to let out of the vessel. Plastic bottles have the ability to expand quite a lot, even with their lids on, or you can use or a large glass bottle or jar with cling film over the top ( tight to the edges but with a little expansion room). Ensure that your vessel that will be almost full with just a couple of cm headroom as this minimises the amount of oxygen in the fermentation vessel, which is a perfect environment for the lactobacilli in the water kefir whilst reducing the risk of contamination by moulds and fungi. You can also use Kilner jars without gaskets (the gaskets are great for a gentle milk kefir fermentation but it’s too extreme for water kefir) I don’t like the way that contaminants could potentially get in through the gaps, but many people use this set up quite happily. I should point out that people ferment water kefir in half full jars just covered with a paper towel too – and report no problems, but I always prefer to err on the side of caution.

How full should the fermentation jar be?

Fill the fermentation vessel with sucrose solution or coconut water so that there are no more than a couple of centimetres of head-room. The bacteria and yeasts in the kefir grains are able to grow well without oxygen, or with just a little oxygen present. Many surface moulds, however, require oxygen to thrive. By having just a little headroom in your vessel, you will make it very difficult for contaminating moulds to grow.

Which kind of sugar should I use?

The bacteria and yeasts in the water kefir grains are going to metabolise the sugar to make CO2, a little ethanol, and some lactic acid. Really we want to make this as easy for them as possible. They also need a few trace minerals to be truly happy so if using refined and thus mineral-depleted sugars, it can be a good idea to include some raisins or other dried fruit. So good old-fashioned white refined sugar works fine, as does organic sugar, or raw sugar, which is good because it has a higher mineral content. Demerara and light brown soft sugar seem to be fine, but anything containing molasses can prevent your grains thriving, so if you want to be experimental with dark brown sugars or molasses, do keep some of your kefir grains safe in case it all goes wrong!

Honey, especially raw honey can be a bit of a struggle as it has antibacterial properties so can inhibit growth of the grains. Again, it rather depends on the specific bacteria and yeasts in the grains, which we don’t exactly know, so experimentation is great, just keep some grains in reserve.

What about metal?

Most domestic grade stainless steel isn’t made for fermenting, as the acid tends to corrode it, so I don’t recommend using a stainless steel fermentation vessel.   But short term contact with a metal spoon and sieve for mere moments? – your kefir, and grains, will be fine. Many folk do end up using plastic sieves and spoons though because of all the anecdotal advice that suggests plastic and glass things are better.

When will it be ready?

The ratio of sugar to water in the solution, the ratio of grains to sugar water in the vessel, and the temperature can all affect the speed of fermentation. Add to that your personal preference for flavour and fizziness and you have a highly variable situation. The grains will grow best between the range 21-28 degrees C. If my kitchen is feeling a little chilly, or my ferment seems a little sluggish I pop them on a shelf in the airing cupboard, which is about 25 C and they are very happy there.  Always check after 24 hours and leave longer if necessary.

What should I use to strain my grains?

The hardest thing about making kefir is the logistics of getting the kefir out of the fermenting vessel into the storage container! At the beginning I used to use a big plastic sieve to strain into a bowl and then transfer using a funnel into a bottle. Very messy. After much research I worked out that a funnel strainer is the answer.

My very favourite thing is the Oxo good grips funnel strainer. It’s perfect for straining into a jar or bottle. The strainer comes out so it can be washed. The only thing that is a worry is losing the strainer bit.   They’re a ridiculous price for what is ostensibly a plastic funnel, but you can get cheaper stainless steel versions ( see “what about metal” above!). If you think a daily dose of Kefir is going to work for you and your family, it’s definitely worth investing in one of these.

I have seen some people try to solve the logistical problem by keeping their kefir grains in a little muslin bag attached to an external string that can be pulled out of the fermentation vessel instead of straining. Whilst on many levels this seems practical, it’s not for me and is potential source of contamination.

 How many grains to use? What’s the ratio?

If you are one of my milk kefir makers you will be used to using just a tiny amount of grains for a large quantity of milk. Things don’t work in the same way for water kefir. Milk is an incredibly complex very rich source of nutrients that those microbes just love. Whilst they like sugar, especially if there are a few minerals too, water kefir’s just not going to go with the same gusto. So you will need to use a lot more grains to make something happen in a couple of days. The ratio I suggest here is about 30g/litre but anything between 20 and 50g a litre will be fine. Either side of that, either reduce the quantity of sugar solution you are using or remove some of the grains and put them in the freezer, experiment with another kind of sugar or give them to a friend.

What about the alcohol content?

There is some alcohol in water kefir because the yeasts especially produce alcohol and CO2, but there are also many lactobacilli and acetobacteria producing acetic and lactic acids. The alcohol content in water kefir is usually around 0.5-0.75%, rather less than you might find in over-ripe fruit. It doesn’t taste alcoholic at all. It is usually judged completely safe to give to children, though praps not a whole pint!

The grains are growing!

Especially in the summer, you will find that the grains increase at an alarming rate! Remove when you notice that they are taking over, and either freeze, share, experiment with or compost. Or mix into smoothies – they can be blended in so no one would know! Milk kefir grains are very popular with dogs – perhaps water kefir ones are too!

Storing and “second-fermenting” water kefir

Those lovely little flip top 250 ml Kilner bottles look like they would be perfect for storing water kefir, but sadly they are not up to the task.   When I started doing this I bought 12 in anticipation; on four out of 12 occasions when opening the bottles, the force of the stored CO2 was so great that it actually broke the top of the bottle and glass flew everywhere.

Grolsh bottles are fine (you just need to find someone to drink the grolsch first J), or normal glass jars with the lids on, or plastic bottles, which can withstand some expansion. I have to say after my Kilner bottle experience I always open bottles with a tea towel over the top just in case. Fill the bottles to about 2 cm of headroom and refrigerate. It will keep in the fridge for 2-3 weeks, but will gradually become more acidic in taste.

Contamination Problems

These are rare with water kefir, especially if culturing in a low oxygen environment where it will be hard for mould to grow. In the unlikely event that there is something fuzzy growing on the surface, throw it away and start again from your frozen stores.

It’s just not working.

If your water kefir grains just aren’t happy, here are a few things you can try.

  1. Try using bottled water with a high mineral content. Perhaps it doesn’t like your water.
  2. Ensure that the sugar you are using doesn’t have any strange caking agents added which the grains mightn’t like
  3. Try adding raisins or other dried fruit without added sulphur. Occasionally this can upset them.
  4. Try reducing the volume of sugar water you are using to the ratio of grains
  5. Email me!

IF you are overrun with water kefir and want to stop.

Put the usual amount of grains in 5% sugar solution in a bottle or jar with a small amount of headroom ( same rules as usual) and leave slightly unturned but not open at the back of the fridge. They will keep quite happily here for up to three weeks but then you will need to change the solution or they will starve.

For longer periods of rest, drain and freeze in a plastic bag.

 Can Everyone have Water Kefir?

As there are no animals involved, water kefir is suitable for vegans and vegetarians. It will probably contain some sugar (unless it has been fermented for over 48 hours whereupon most will have been metabolised) which diabetics should be aware of. It’s possible to quantify how much using a hydrometer and testing the sugar content before and after fermentation ( they are £4.99 from Amazon – very interesting devices!).

Water kefir does contain traces alcohol. If you are going to give lots of it to young children it might be worth knowing that using the hydrometer can help you to tell if alcohol is present. It will tell you a maximum amount of glucose that could have been converted to alcohol. You can then guesstimate that only some of this will have been converted into alcohol because most of the sugar is actually used by lactic acid bacteria and acetic actid bacteria to make other things than alcohol. You will probably arrive at a figure of 0.5% or less.

Is it as good for you as milk kefir?

Water kefir is a source of probiotic bacteria. It is worth noting, however, that is does not confer as many health benefits as milk kefir because it contains far fewer bioactive peptides and no short chain fatty acids. The by-products from milk fermentation have wide-ranging physiological actions.

Still, definitely worth drinking in preference to usual carbonated drinks, with less sugar and a healthy dose of probiotic bacteria. Drinking water kefir with our meals has greatly reduced midweek wine consumption in our family 🙂

Some of the best flavour combinations:

These can be added either to plain water kefir and served straight away, or fermented for a further 24-48h after straining out the grains, to further reduce the sweetness.

Elderflower cordial

Rhubarb syrup ( from left over cooked rhubarb)

Stawberry syrup ( from cooked strawberries)

Ginger syrup ( from a jar)

Orange water

Rose water

Fresh additions for secondary fermentation:

Rosemary sprigs ( washed)

Mint leaves ( though you need quite a few to make some flavour)

Apple slices

Pineapple and vanilla

A small cube of ginger