Kombucha is everywhere – from supermarket shelves to cafes, the local bar scene and even your health-conscious friend who has a jar of the stuff brewing at home.
But if you think it’s a new beverage, people in China were already making and drinking it thousands of years ago. The fermented sugared tea (that’s what it is essentially) is probably the latest drink to join detox juices, smoothies, protein shakes and a menagerie of health beverages in recent years.
Its slightly tart, mildly sweet and fizzy nature is thanks to weeks of fermentation by the SCOBY, short for the symbiotic colony of bacteria and yeast added to the tea. Kombucha is sometimes called “mushroom tea” because of the micro-organism-rich, mushroom-like film found on the surface of the liquid.
But that’s not the only part of kombucha where the supposedly beneficial bacteria or probiotics is found. The friendly microbes are also thought to grow in the mixture – and that’s what’s getting enthusiasts excited about the drink.
But how much do we all really know about it? Here are some questions you might have. CAN KOMBUCHA REALLY HELP WITH DIGESTION? Remember when yoghurt first hit the health food scene as the fermented food du jour? If its cool, creamy, rich texture didn’t already win you over then, its litany of health benefits might have gotten you intrigued.
And it seems history is repeating itself with kombucha. A quick Google search on the drink’s benefits would get you a list ranging from better digestion to weight loss, improved blood sugar levels, lower heart disease risks and even cancer prevention. But can it really do all that?
Pregnant and breastfeeding women, and individuals with compromised immune systems or known allergies to alcohol should avoid kombucha. The drink does have several species of lactic acid bacteria, according to a study published in Food Microbiology. However, the study noted that there is still no evidence that support the probiotic benefits of kombucha.
"There are few controlled studies examining the health benefits of kombucha in humans," said dietitian Goh Qiu Le with Changi General Hospital's Dietetic & Food Services. Dr Brent Bauer, the director of the Department of Internal Medicine's Complementary and Integrative Medicine Program at Mayo Clinic, also doubted its probiotic function: “Limited evidence suggests kombucha tea may offer benefits similar to probiotic supplements, including promoting a healthy immune system and preventing constipation”. WHAT ABOUT OTHER "BENEFITS" SUCH AS PREVENTING CANCER? There are claims that kombucha could help your body detox as well as prevent and manage health conditions, from blood pressure to cancer. What do the experts think? “Most of kombucha’s claims appear to be overstated,” said Jaclyn Reutens, the founder and dietitian at Aptima Nutrition & Sports Consultants.
"Further studies are needed to validate and/or debunk these otherwise anecdotal and hypothetical health claims," said Goh. Dr Bauer also wrote on mayoclinic.org that “these claims are not backed by science. At present, valid medical studies of kombucha tea’s role in human health are very limited”.
IS HOME-BREWED KOMBUCHA SAFE? If you’re brewing your own kombucha, be careful. Letting nature take over sugar-rich solutions can sometimes invite harmful pathogens such as E coli to grow, too, said Li Zhaoping, a professor of medicine and the chief of University of California, Los Angeles’s Division of Clinical Nutrition.
Reutens cautioned that “you can inadvertently add other bacteria from poor food handling” or allow “pathogenic bacteria and mould” to multiply when the kombucha “has not been sealed and stored adequately”. Furthermore, there is no standard to benchmark good or safe kombucha against because “there is no gold standard recipe of tea, sugar and SCOBY to be used”, said Reutens. And there isn’t a home kit to let you test your brew’s nutritional value or safety, except maybe smell and taste.
So how should kombucha taste like then? "Its flavour profile is comparable to that of apple cider vinegar – tart yet slightly sweet," said Goh. Another way to gauge your home-made kombucha's safety is to test its pH, he said. "The fermentation process lowers the sugared tea's pH from ≥5 to approximately 2.5 over seven to 10 days. If a pH of 2.5 has not been reached by Day 10, the liquid should be discarded."
In fact, Prof Li advised against home brews, especially if they’re made for older people or those with compromised immune systems, as they are not pasteurised.
"Pregnant and breastfeeding women, and individuals with known allergies to alcohol should also avoid kombucha," added Goh.
You cannot get kombucha without sugar because sugar is the substrate for the SCOBY. Your best bet is to look at the “per 100ml” column and pick the one with the least amount of sugar. Those who don’t imbibe and those with severe irritable bowel syndrome should avoid kombucha as well since it contains alcohol and can exacerbate diarrhoea, said Reutens. “If you are drinking a highly sweetened kombucha in large quantities, you could end up putting on some weight.”
CAN STORE-BOUGHT KOMBUCHA REALLY BE SUGAR FREE? Speaking of weight gain, just how many calories does kombucha have? A 500ml store-bought bottle can have up to 100 calories, which come mainly from sugar; flavoured options may have more, said Reutens.
Kombucha definitely has a lower calorie count than soft drinks but even so, it is not sugar-free. “You cannot get kombucha without sugar because sugar is the substrate for the SCOBY,” said Reutens. “The sugar can be listed as sucrose, honey, cane sugar, brown sugar, beet sugar, maple syrup or agave." Be wary if the label reads "sugar free" or "no sugar". Check the ingredients list instead. Goh highlighted that "excessive sugar is sometimes added to mask the tangy taste of kombucha" and make it more appealing to consumers. Your best bet? Look at the “per 100ml” column and pick the one with the least amount of sugar, advised Reutens.
WHAT ELSE IS IN THAT BOTTLE OF KOMBUCHA YOU GOT FROM THE SUPERMARKET? Because the beverage is made of tea, kombucha can contain polyphenols – the antioxidants that tea is known to have. But if that's your reason for drinking kombucha, you might be better off drinking plain black or green tea without sugar, said Reutens.
Neither is kombucha alcohol-free, despite claims on the bottle, as it can contain anywhere from 0.5 per cent to 3 per cent alcohol. Manufacturers are allowed to label the drink as non-alcoholic if it contains less than 0.5 per cent alcohol, said Reutens.
As for kombucha-infused cocktails and drinks at bars and wellness cafes, Goh doubted their nutritional benefits. "The addition of kombucha to alcohol does nothing for the beverage from a nutritional standpoint."
Also, ensure that the kombucha is refrigerated and not placed on the shelf at room temperature, said Goh. "Authentic kombucha, which is essentially a symbiotic collection of bacteria and yeast, should look murky with floating strands."