What I know about Kombucha:
1) It is the product of tea, sugar, and a Symbiotic Colony Of Bacteria and Yeast (SCOBY for short).
2) Moderate consumption of Kombucha has helped me personally reduce cravings for Coffee, Alcohol, and Carbohydrates. I feel better when I consume less of these, especially Carbohydrates.
3) While it is commercially available I like what I make myself much better because:
4) Specific compounds in Kombucha have known health benefits.
5) There is no mushroom or fungus involved.
What I don’t know about Kombucha: A lot.
However, when I see “scientific commentary” about something I consume like honey, eggs, or Kombucha I am always concerned about who is paying for the science. Pharmaceutical companies and agribusiness don’t like things which are hard to replicate. Like the complex interaction of bees in their environment to produce raw honey which is better for you than sterile controllable cane sugar. Raw Honey and strained factory honey bears the same relationship as artisan cheese does with pasteurized cheese food.
I am also concerned the scientist in question is actually working in his area of expertise. A specialist in mushrooms is probably not qualified to comment on fermentation driven by yeast and bacteria. There is a lot of junk science on the internet. Ten seconds on Google will provide equally convincing opposing “science”.
I see these same kinds of arguments used to suppress artisan cheeses, raw milk production, raw honey, and eggs from urban chickens. Lots of the things that are clearly better when produced on a less than industrial scale.
Lots of food can be made badly in your own home. Careful thought about how you are going about things can make a huge difference. I wouldn’t recommend anyone produce Kombucha jar by jar restarting the process over every time. You have to work too hard and the process has lots of points where contamination is a problem. Continuous brew is a superior option because it maintains pH at a level where the SCOBY suppresses competition and allows more complex compounds with known health benefits to form.
Many foods have antibiotic compounds or properties, like cranberry juice, which is specific for urinary tract infections. Many things you consume every day produced by the agriculture industry have antibiotic, hormonal or chemical content as a result of poor practices involving treating animals and plants for problems they do not have. Now that is something I am worried about.
The Kombucha SCOBY is related to the Mother of Vinegar used in Vinegar production. It can become a Mother of Vinegar if mishandled. I am guessing the reverse is possible as well. Should we stop using vinegar too? Home-brewed beer is probably a bad idea as well. I have heard some real horror stories.
I have no clue as to the mystical origin of Kombucha, or yogurt, or lots of fermented foods. I don’t care either. It doesn’t matter. What does matter is that this is a legitimate wild brewed/fermented substance which can provide real and measurable benefits. I would suggest anyone interested in Kombucha start slowly and see what happens to them personally. I would not suggest anyone with a suppressed immune system have anything fermented without checking with a doctor. I eat kale and sourkraut because they are good for me, and I am happier when I have them. The same goes for Kombucha.
There are people out there that want to convince you (because it sells advertising) the internet is a scary place you should stay away from. When you engage in homemade fermentation or accessing the internet, you must take responsibility for your own actions, pay attention to the process, and monitor your result.