Forget sourdough, chuck out your kimchi, true culture vultures are now drinking fermented H20... but would you pay £8 for water that's full of bacteria?
Now we know that fermented products are great for our gut health, there's no stopping us. We're sipping tart kombucha tea, baking sourdough and adding kimchi to our stir fries.
But move over kombucha, there's a new 'live' drink in town that's fast becoming a favourite — water kefir.
It is a fermented drink, made from combining water, sugar, and kefir 'grain' cultures — so called because these live organisms resemble grains.
'When you feed the cultures sugar in water, it starts the fermentation process,' says Eve Kalinik, nutritional therapist and author of Happy Gut, Happy Mind: How To Feel Good From Within.
Water kefir is made from combining water, sugar and kefir 'grain' cultures
As the kefir cultures metabolise the sugar, 'they produce certain beneficial substances and multiply, thus increasing the number of beneficial microbes in the drink that are good for our gut health,' Eve says.
'Water kefir tends to be high in the lactic acid bacteria. There's also some yeast in there.'
The resulting beverage is very low in sugar, low alcohol (typically 0.5 per cent), naturally mildly fizzy, and contains B vitamins and probiotic cultures that aid digestion and can help to re-populate our gut with beneficial bacteria.
For those of us who have only just discovered yoghurt kefir, should we switch? The difference is that milk kefir cultures feed on lactose, whereas water kefir cultures feed on sugars.
Eve says, 'I would say it's not an either or. You get different types of bacteria from different fermented products.
'We know that the health of the gut microbiome the bacteria and other microbes in the is dependent on diversity in the fibre that we eat, and in the microbes we ingest.
'Try to mix and match.'
Although it contributes to gut health, is water kefir worth it?
It seems so. Eve says, 'The health of our gut affects the health of our immune system, how we manage inflammation, not just in the gut, but more broadly — and it has an impact on how our brain is functioning.
'It's not just about digestion.' With this in mind, we tried six water kefirs to see if they were hard to stomach or went down a treat . . .
DRINK THE GOODNESS
Pleasingly tart, this tastes like sparkling lemonade. It has a sophisticated, satisfying depth of flavour, partly because it naturally contains a tiny amount of alcohol.
Though brewed in small batches in London, it's made from the Tibicos (another name for water kefir) Mother Culture — discovered 2,000 years ago on the pads of the Mexican Opuntia cactus — and boasts 55 billion gut-friendly live cultures.
The pomegranate and hibiscus option, which looks like rosé, is easy to drink — if you're off booze this is ideal.
(It contains 26 calories and 3.4g of sugar per 100ml — but because it's a live drink and the sugar continues to be fermented and metabolised by the bacteria, it will be less than 3.4g of sugar when consumed.)
It's neither too sweet nor too sharp — the perfect drink.
Verdict: 5/5
SUGAR-FREE SIP
Eugh is my response to cracking open this can. Its ingredients are carbonated water, organic coconut water, sugar (though none remains after the fermentation process) and kefir culture. (It also contains only five calories, and zero sugar.)
The scent is synthetic. I take a sip and it makes my stomach turn.
I'm fussy about coconut flavours, finding the slightest soapy edge unacceptable.
It also contains flavour enhancer erythritol, natural coconut flavouring and stevia, a natural sweetener, which may be why this kefir and I don't get along.
There's no need to refrigerate it because while the drink is live cultured, it's also naturally sugar-free, and 'no sugar means no risk of re-fermentation'.
Verdict: 2/5
BLUE FIZZ
Purearth has a pastel range of flavours, and its sparkling lemon + spirulina is a pretty pale blue.
There's a faint, brief sulphurous whiff but it has a gentle, pleasant taste, reminiscent of a light lemonade.
It's naturally sparkling but digestible. A mere 100ml contains ten billion live cultures.
(It only has 18.9 calories and 2.7g of sugar per bottle.)
It also has vitamins B2 and B12, which support the immune system function and reduce fatigue.
Verdict: 4/5
LOW-CALORIE FARE
The London Fermentary has a range of water kefirs the colours of semi-precious stones, all infused with fresh fruit and botanicals.
The naturally purple-tinted Calming Lavender is wonderful, boasting delicate herbal notes.
It's tart and refreshing, a special, elegant drink.
This artisan firm — which specialises in fermented produce — uses a small amount of organic sugar, metabolised by bacteria during the fermentation process, releasing lactic acids, minerals and enzymes.
Just 100ml contains more than 160 billion gut-friendly lactic acid bacteria and is only 12 calories and 1.5g sugar per bottle.
Verdict: 5/5
THIRST QUENCHER
This has a crisp, fruity flavour — it's 9.6 per cent pomegranate juice and 1.6 per cent cranberry juice — which makes it's very drinkable.
It reminds me of a fizzy apple juice.
It's only 26.4 calories per bottle and slightly higher in sugars (though only 6.3g in total) than some of the others because of the fruit juice, but there's no cloying sweetness — it's perfectly balanced.
It has that thirst-quenching bite of a good lager and is very refreshing.
Verdict: 5/5
PRICEY ORGANIC SHOT
This tastes of sharp, fizzy coconut. It's a serious high-potency water kefir (the brand was recently selected by university scientists to be part of a UK clinical trial to assess the benefits of fermented foods to our health).
Its price, reflective of this, might make you wince.
It's made from raw cold pressed coconut milk, unflavoured beyond that, with no added sugar — so one has to be a little bit brave.
It's in shot form, packaged in 100ml bottles, so mercifully quick.
But that said — hand on heart — it's not unpleasant.
It's excellent quality and very good for you — containing over 100 billion live, diverse, active gut-friendly cultures to boost immunity and reduce inflammation.
(And only 2g of sugar and 34 calories.) I'd down it in the morning, and feel very pleased with myself — I just wouldn't serve it at dinner parties.
Verdict: 4/5