Countless health claims swirl around kombucha, a fermented drink made with tea, sugar, bacteria and yeast.
Although there is little research backing up the would-be superfood benefits of kombucha, some studies have suggested that it can help with gut health in place of probiotic supplements, and also support the body’s immune system.
The risks of this drink are clearer, however, for vulnerable groups such as pregnant women, young children and anyone with a weak immune system.
What’s more, if it’s made at home in unsafe conditions, unwanted bacteria that grows in it can cause allergic reactions, infections and an upset stomach.
In many countries, the rules defining how the drink is made are unclear, and depending on the supplier, kombucha can therefore taste different and have different ingredients.
Certain groups of people should be careful or avoid it altogether.
Because kombucha contains small amounts of alcohol, pregnant women, breastfeeding mothers, infants, small children and dry alcoholics (i.e. a recovering alcoholic who has stopped drinking, but still displays the same dysfunctional behaviours they had while they were drinking) should avoid it.
Germany’s Federal Nutrition Centre (BZfE) also warns people with a weak immune system or pre-existing conditions such as kidney failure, to steer clear of it out of precaution.
This is especially pertinent when it comes to unfamiliar products where production methods are not standardised.
Hygiene is a top priority when kombucha is made at home, and it’s essential to use sterile containers.
It’s also best to use a glass container because the acidity of the fermented drink can dissolve the lead from ceramics with a lead- containing glaze, and in the worst case, lead to lead poisoning if consumed over a long period of time.
The basic ingredients are usually black or green tea, sugar and Scoby, which stands for “Symbiotic Culture of Bacteria and Yeasts”.
First, boil water and leave the sweetened tea to infuse for around 10 minutes.
If you like, you can also let it infuse with some fruit, herbs, or even vegetables.
Then to the cooled, filtered liquid, add at least 10% of your starter liquid.
This helps to ferment the tea at room temperature, which is converted into carbon dioxide and alcohol, and further metabolised by the bacteria.
This produces organic acids such as acetic, lactic and gluconic acid.
Detailed recipes can be found online and in books.
Depending on the mixture and how long it’s left to ferment, the finished drink tastes somewhere between sweet and tart or sour.
Important: If mould forms or the colour or smell changes, the entire culture must be thrown away, since consuming kombucha made with this could mean negative health effects. – dpa