John Myers
The tea drink Kombucha is offered as an “elixir of life” and a remedy for almost all diseases. However, the advertised effects have not been scientifically proven.
The essentials in brief:
- Kombucha is a sugared tea fermented with the help of a mixture of bacteria and yeast. It contains up to 2% alcohol.
- Kombucha is more of a kind of soft drink, not a cure.
- There is a suspicion of harmful effects in rare cases.
- Anyone who produces Kombucha themselves must attach particular importance to hygiene.
The tea drink Kombucha is offered as an “elixir of life” and a remedy for almost all diseases. However, the advertised effects have not been scientifically proven.
The tea is said to improve intestinal function, activate the immune system and stimulate the metabolism as well as cleanse the blood. Kombucha is recommended for numerous diseases: for example gout, rheumatism, impure skin and also as protection against cancer and cardiovascular diseases. Such disease-related statements are not only not scientifically proven, they are also prohibited. Current systematic overview studies have only found case reports on side effects (see below), but no evidence of positive effects.
What is kombucha?
Kombucha is made with the so-called tea or kombucha fungus, a jelly-like substance containing a mixture of different bacteria and yeasts. Therefore, the Kombucha culture is also referred to as SCOBY (“symbiotic culture of bacteria and yeast”). This ferments sugared tea into a cider-like, carbonated drink. During fermentation, alcohol and acetic acid, lactic acid and gluconic acid are formed from the added sugar. As a result, Kombucha tastes sour and contains between 0.7 and 1.3 percent alcohol.
Kombucha was originally part of Asian folk medicine. With us, the tea fungus is mainly available in health food stores and health food stores, but is also often passed on from hand to hand. As a ready-to-drink kombucha can be found in food and beverage stores.
What is the finished drink made of?
Kombucha is made from sweetened herbal tea, green tea or black tea. Depending on the preparation and fermentation time, it sometimes contains as much sugar as lemonade (up to 10 percent). Carbon dioxide, various acids, especially acetic acid, lactic acid and gluconic acid, and alcohol (0.1 to 2%) are also produced during fermentation. Homemade kombucha contains living microorganisms.
How healthy is kombucha?
Properly prepared Kombucha is a harmless soft drink, whereby the content of alcohol, caffeine and possibly sugar must be taken into account. Its health effects are comparable to those of other fermented foods, such as sour milk products, whose microorganisms can have a positive effect on the intestinal flora.
However, the extent of this effect is unknown for kombucha. Scientifically proven are only slightly laxative and weak antibacterial effects, which are due to the content of acetic and lactic acid.
Industrially produced kombucha is pasteurized for reasons of shelf life. This kills the microorganisms in the fermentation drink – they become ineffective. If you are hoping for additional effects, you should only buy products with live cultures.
What should be considered during production?
If you make kombucha yourself, you have to pay special attention to hygiene. Kombucha contaminated with foreign germs, especially with mold (-poisons), can cause problems for sensitive people, especially people with an immune deficiency.
When preparing, please note:
- Hands, fermentation vessel (no ceramic!) and equipment must be thoroughly cleaned with hot water before each new batch.
- About 100 milliliters of the finished drink are added to the starter liquid.
- To prevent insect infestation, you need to cover the fermenter with a cloth and secure it with a canning gum.
- If mold develops or there is a change in color and odor, you must discard the entire culture.
When preparing at home, make sure you use a suitable container (e.g. glass). For example, people who regularly drank kombucha for half a year that had been prepared in a ceramic vessel with a glaze containing lead suffered from lead poisoning. The acid from the fermented drink can dissolve the lead from the glaze.
Possible harmful effects
There are isolated reports of people who have had allergic reactions, nausea, muscle inflammation, dangerous acidification of the blood (which resulted in death in one case), or liver disease after consuming kombucha.
In most cases it was home-made kombucha, sometimes the source is not recorded. It is possible that the respective homemade kombucha batch was contaminated with harmful microorganisms.
However, these case reports cannot prove that the cause of the serious health problems was actually kombucha.
Conclusion
From a food law perspective, kombucha is a drink of its own kind with a low alcohol content (0.1-2%). In any case, it serves as a refreshment, but not as a remedy. The proportion of sugar, alcohol and caffeine varies greatly. Some commercially available products are suitable as low-calorie thirst quenchers. However, the high selling price of up to 4 euros and more per liter is offset by a questionable benefit.
