Kombucha seemed to be on everyone's mind last weekend -- for example, it's been a top trending term on Google. As a fan of the fermented tea, I am surprised and heartened by this development. I make the tea at home, because it is easy and fun to do, resulting in a fizzy, amber-colored drink with a tangy, almost vinegar-like taste and sweet, herbal back notes. As many brewers may relate to, I've become something of a 'buch pusher -- offering the stuff to friends, coworkers and even neighbors. And at $4 a bottle for store-bought kombucha, I'm happy to share the wealth with far cheaper home brew.
I start by combining strong-brewed, sweetened, usually black or green teas with a bit of already prepared kombucha and a dense, silicone-like disc called a SCOBY, which stands for symbiotic culture of bacteria and yeast. This culture acts the way a 'mother' starter does for sourdough bread. After about 10 days, the yeast and bacteria have metabolized about 95 percent of the sugar, excreting hundreds of compounds, including lactic acid, alcohol, and B vitamins. It is these byproducts that kombucha drinkers prize. But is the drink actually a health tonic?
As a health reporter, I've managed to find a place as something of a medical authority among my friends. (What can I say? In the land of English majors, the one-eyed man is king). I'm not a doctor, but it is my job to review medical information and check claims with leading researchers. So when friends ask me if kombucha is really good for you, I say with great confidence: I have no idea.
The truth is that the research is inconclusive. There has yet to be a single clinical study of human kombucha consumption and studies that do show some benefit have generally been preliminary and in animals. Some of those have shown promise: in one 2010 experiment published in the journal Food & Function, researchers fed kombucha to mice with stomach ulcers and found that black tea that was fermented for four days with a Kombucha culture was as effective in treating the ulcers as the control medication, omeprazole. And in 2003, researchers administered kombucha to rats who had previously received doses of lead acetate. They found that the tea helped improve the rats' immune systems, which were suppressed as they tried to process the heavy metal.
On the other hand, there have been reports of some dangers associated with making the tea at home. In one case, the Centers for Disease Control and Prevention reported an outbreak of unexplained illness that sickened one person and killed another in Iowa in 1995 -- it was eventually attributed to contaminated homemade kombucha derived from the same SCOBY. Just as with any home food preparation, there is the danger of contamination.
A different health concern, alcohol content, came to the fore in 2010 when the FDA sent warning letters to several commercial kombucha manufacturers, including industry leader, GT Dave, after they found that the tea had far higher alcohol levels -- sometimes as high as 3 percent -- than are allowed in non-controlled beverages.
Still, those who swear by kombucha say that it stimulates digestion, the immune system and improves liver function. They say that as a result of drinking it, they sleep better, have clearer skin and thicker hair.
Somewhat controversially, many people with compromised immune systems, such as cancer patients and those living with HIV -- including a well-known fermented food specialist, Sandor Ellix Katz, who is the author of Wild Fermentation -- count the brew as a supplementary therapy that helps keep white blood cell counts up. But it's important to note that oncologists and other specialists who treat immunocompromised patients disagree.
In an informational section about kombucha, doctors from Memorial Sloan-Kettering Cancer Center, a cancer hospital in New York City, warn that "patients with suppressed immune systems should not consume Kombucha beverages produced in an uncontrolled environment."
I can say that as an otherwise healthy individual, it makes me feel more alert and it has helped me with personal concerns, like headaches and staving off cold and flu in the winter months.
Is it the placebo effect? Possibly. This is no clinical study; I am an N of 1. But the drink is low-sugar, low-caffeine and hydrating. It works for me, so I'm going to let me 'buch flag fly. Do you drink the stuff? If so, why?