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Kombucha (Russian: chaynyy grib (чайный гриб), Chinese: chájūn (茶菌), Korean: hongchabeoseotcha (홍차버섯차), Japanese: kōcha-kinoko (紅茶キノコ)), is a lightly effervescent fermented drink of sweetened black and/or green tea that is used as a functional food. It is produced by fermenting the tea using a symbiotic colony of bacteria and yeast (SCOBY).

There have not been any human trials conducted to confirm any curative claims associated with the consumption of kombucha tea.A small number of random anecdotal reports have raised concern over the potential for contamination during home preparation, as well as toxicity concerns due in part to the leaching of lead in ceramic containers during fermentation.

Etymology

In Japan, Konbucha (昆布茶, "kelp tea") refers to a different beverage made from dried and powdered kombu (an edible kelp from the Laminariaceae family). For the origin of the English word kombucha, in use since at least 1991 and of uncertain etymology, the American Heritage Dictionary suggests: "Probably from Japanese kombucha, tea made from kombu (the Japanese word for kelp perhaps being used by English speakers to designate fermented tea due to confusion or because the thick gelatinous film produced by the kombucha culture was thought to resemble seaweed)."

The Japanese name for what English speakers know as kombucha is kōcha kinoko 紅茶キノコ (literally, 'black tea mushroom'), compounding kōcha "black tea" and kinoko 茸 "mushroom; toadstool". The Chinese names for kombucha are hóngchájùn 红茶菌 ('red tea fungus'), cháméijūn 茶黴菌 ('tea mold'), or hóngchágū 红茶菇 ('red tea mushroom'), with jūn 菌 'fungus, bacterium or germ' (or jùn 'mushroom'), méijūn 黴菌 'mold or fungus', and gū 菇 'mushroom'. ("Red tea", 紅茶, in Chinese languages corresponds to English "black tea".)

A 1965 mycological study called kombucha "tea fungus" and listed other names: "teeschwamm, Japanese or Indonesian tea fungus, kombucha, wunderpilz, hongo, cajnij, fungus japonicus, and teekwass". Some further spellings and synonyms include combucha and tschambucco, and haipao, kargasok tea, kwassan, Manchurian fungus or mushroom, spumonto, as well as the misnomers champagne of life, and chai from the sea.

History

Kombucha most likely originated in Northeast China or Manchuria later spreading to east Russia sometime before 1910 and from there, to Europe. In Russian, the kombucha culture is called chainyy grib чайный гриб (literally "tea fungus/mushroom"), and the fermented drink is called chainyy grib, grib ("fungus; mushroom"), or chainyy kvas чайный квас ("tea kvass"). Kombucha was highly popular and seen as a health food in China in the 1950s and 1960s. Many families grew kombucha at home. No historical records show use in ancient China or Japan (see history of tea in China and history of tea in Japan). NBC News has reported that the drink is 2,000 years old.

Kombucha's English name is derived from Japanese. According to folklore, it was introduced to Japan by a Korean doctor named Kombu as a health tonic.

Chemical and biological properties

A kombucha culture is a symbiotic culture of bacteria and yeast (SCOBY), containing Acetobacter (a genus of acetic acid bacteria) and one or more yeasts, which form a zoogleal mat. In Chinese, the microbial culture is called haomo in Cantonese, or jiaomu in Mandarin, (Chinese: 酵母; lit. 'fermentation mother'). It is also known as Manchurian Mushroom.

Kombucha cultures may contain one or more of the yeasts Saccharomyces cerevisiae, Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii, and Zygosaccharomyces bailii.

Although the bacterial component of a kombucha culture comprises several species, it almost always includes Gluconacetobacter xylinus (formerly Acetobacter xylinum), which ferments the alcohol(s) produced by the yeast(s) into acetic acid, increasing the acidity while limiting the kombucha's alcoholic content. The number of bacteria and yeasts that were found to produce acetic acid increased for the first four days of fermentation, decreasing thereafter. Sucrose gets broken down into fructose and glucose, and the bacteria and yeast convert the glucose and fructose into gluconic acid and acetic acid, respectively. G. xylinum is responsible for most or all of the physical structure of a kombucha mother, and has been shown to produce microbial cellulose, likely due to selection over time for firmer and more robust cultures by brewers.

Along with multiple species of yeast and bacteria, Kombucha contains organic acids, active enzymes, amino acids, and polyphenols they produce. The exact quantities of these items vary between samples, but may contain: acetic acid, ethanol, gluconic acid, glucuronic acid, glycerol, lactic acid, usnic acid and B-vitamins. Kombucha has also been found to contain about 1.51 mg/mL of vitamin C.

As a result of kombucha's high acidic properties, caution must be exercised during home preparation to prevent contamination and the leaching of potentially toxic levels of lead associated with fermentation in ceramic containers.

According to the American Alcohol and Tobacco Tax and Trade Bureau, many kombucha products contain more than 0.5% alcohol by volume, but some contain less.

The acidity and mild alcoholic element of kombucha resists contamination by most airborne molds or bacterial spores. A study showed that kombucha inhibits growth of harmful microorganisms such as E. coli, Sal. enteritidis, Sal. typhimurium, and Sh. sonnei. As a result, kombucha is relatively easy to maintain as a culture outside of sterile conditions. The bacteria and yeasts in kombucha promoted microbial growth for the first six days of fermentation; after that, they steadily declined. Kombucha retained its antimicrobial capability even after being heated, and at a pH of 7. While the beverage inhibited growth of certain bacteria, it had no effect on the yeasts. The study also found that large proteins and catechins such as Epigallocatechin gallate also contributed to the antimicrobial properties of kombucha.

Kombucha tea has antioxidant properties, and has been called a functional food.

Kombucha culture can also be used to make artificial leather, for example London based fashion designer Suzanne Lee is experimenting with creating jackets and shoes.

Health effects

Kombucha has been promoted with claims that it can treat a variety of human illnesses including AIDS, cancer, and diabetes, and that it can stimulate the immune system. Although laboratory experiments are suggestive of possible health effects, there is no evidence that kombucha consumption benefits human health. There have not been any human trials conducted to confirm any curative claims associated with the consumption of kombucha tea. 

Some adverse health effects may be due to the acidity of the tea; brewers have been cautioned to avoid over-fermentation.

See also

• Kefir
• List of ineffective cancer treatments
• Tibicos

References

1. ^ Jayabalan, R; Malbaša, RV; Lončar, ES; Vitas, JS; Sathishkumar, M (July 2014). "A Review on Kombucha Tea — Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus". Comprehensive Reviews in Food Science and Food Safety. 13 (4): 538–50. doi:10.1111/1541-4337.12073. a source of pharmacologically active molecules, an important member of the antioxidant food group, and a functional food with potential beneficial health properties.
2. Wong, Crystal. (12 July 2007). "U.S. 'kombucha': Smelly and No Kelp". Japan Times. Retrieved 14 June 2015..
3. O'Neill, Molly (28 December 1994). "A Magic Mushroom Or a Toxic Fad?". New York Times. Retrieved 14 June 2015.
4. Algeo, John; Algeo, Adele (1997). "Among the New Words". American Speech. 72 (2): 183–97. doi:10.2307/455789. JSTOR 455789.
5. American Heritage Dictionary, 4th ed. 2000, updated 2009, Houghton Mifflin Company. kombucha, TheFreeDictionary.com.
6. Hesseltine, C. W. (1965). "A Millennium of Fungi, Food, and Fermentation". Mycologia. 57 (2): 149–97. doi:10.2307/3756821. JSTOR 3756821. PMID 14261924.
7. "Kombucha". Memorial Sloan Kettering Cancer Center. 22 May 2014. Retrieved June 2015. {{cite web}}: Check date values in: |accessdate= (help)
8. ^ Sreeramulu, G; Zhu, Y; Knol, W (2000). "Kombucha fermentation and its antimicrobial activity". Journal of Agricultural and Food Chemistry. 48 (6): 2589–94. doi:10.1021/jf991333m. PMID 10888589.
9. ^ Helm, Janet. "Trendy Fizzy Drink is Mushrooming". NBC News. Retrieved 6 June 2015.
10. Nguyen, VT; Flanagan, B; Gidley, MJ; Dykes, GA (2008). "Characterization of cellulose production by a gluconacetobacter xylinus strain from kombucha". Current Microbiology. 57 (5): 449–53. doi:10.1007/s00284-008-9228-3. PMID 18704575.
11. Teoh, AL; Heard, G; Cox, J (2004). "Yeast ecology of kombucha fermentation". International Journal of Food Microbiology. 95 (2): 119–26. doi:10.1016/j.ijfoodmicro.2003.12.020. PMID 15282124.
12. Dufresne, C; Farnworth, E (2000). "Tea, kombucha, and health: A review". Food Research International. 33 (6): 409. doi:10.1016/S0963-9969(00)00067-3.
13. Velicanski, A; Cvetkovic, D; Markov, S; Tumbas, V; Savatovic, S (2007). "Antimicrobial and antioxidant activity of lemon balm Kombucha". Acta Periodica Technologica (38): 165–72. doi:10.2298/APT0738165V. {{cite journal}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)
14. Bauer-Petrovska, B; Petrushevska-Tozi, L (2000). "Mineral and water soluble vitamin content in the kombucha drink". International Journal of Food Science & Technology. 35 (2): 201–5. doi:10.1046/j.1365-2621.2000.00342.x.
15. "Kombucha FAQs" (PDF). Alcohol and Tobacco Tax and Trade Bureau. Retrieved August 2013. {{cite web}}: Check date values in: |accessdate= (help)
16. ^ Jayabalan, Rasu; Malbaša, Radomir V.; Lončar, Eva S.; Vitas, Jasmina S.; Sathishkumar, Muthuswamy (2014). "A Review on Kombucha Tea–Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus". Comprehensive Reviews in Food Science and Food Safety. 13 (4): 538–550. doi:10.1111/1541-4337.12073. ISSN 1541-4337. There has been no evidence published to date on the biological activities of kombucha in human trials.
17. "Suzanne Lee: Grow your own clothes". TED2011. March 2011.
18. Vīna I, Semjonovs P, Linde R, Deniņa I (2014). "Current evidence on physiological activity and expected health effects of kombucha fermented beverage". J Med Food (Review). 17 (2): 179–88. doi:10.1089/jmf.2013.0031. PMID 24192111.
19. Nummer, Brian A. (2013). "Kombucha Brewing Under the Food and Drug Administration Model Food Code: Risk Analysis and Processing Guidance". Journal of Environmental Health. 76 (4).

Further reading

• Dasgupta A, Sepulveda JL (2013). Other Supplements that Cause Liver Damage. Elsevier. pp. 78–79. ISBN 978-0-12-415858-0. the limited evidence currently available raises safety concerns, especally regarding potential hepatotoxicty and the possibility of life-threatening lactic acidosis {{cite book}}: |work= ignored (help)
• Dipti, P; Yogesh, B; Kain, A. K.; Pauline, T; Anju, B; Sairam, M; Singh, B; Mongia, S. S.; Kumar, G. I.; Selvamurthy, W (September 2003). "Lead induced oxidative stress: beneficial effects of Kombucha tea". Biomedical and environmental sciences : BES. 16 (3): 276–82. PMID 14631833.
• Frank, Günther W. (1995). Kombucha: Healthy Beverage and Natural Remedy from the Far East, Its Correct Preparation and Use. Steyr: Pub. House W. Ennsthaler. ISBN 978-3-85068-337-1.
• Pauline, T; Dipti, P; Anju, B; Kavimani, S; Sharma, S. K.; Kain, A. K.; Sarada, S. K.; Sairam, M; Ilavazhagan, G; Devendra, K; Selvamurthy, W (September 2001). "Studies on toxicity, anti-stress and hepato-protective properties of Kombucha tea". Biomedical and environmental sciences : BES. 14 (3): 207–13. PMID 11723720.

External links

• A microscope video of concentrated tea after a few hours on the slide
• A microscope video of fresh tea, more typical of the finished product that people drink

• Carbonated drinks
• Chinese tea
• Fermented beverages
• Fermented foods
• Mycology
• Blended tea
• Toxicology