SCOBY

A SCOBY used for brewing kombucha

A SCOBY (for symbiotic culture of bacteria and yeast) is a syntrophic mixed culture, generally associated with kombucha production wherein anaerobic ethanol fermentation (by yeast), anaerobic organic acid fermentation (by bacteria), and aerobic ethanol oxidation to acetate (by bacteria) all take place concurrently along an oxygen gradient. A gelatinous, cellulose-based biofilm called a pellicle forms at the air-liquid interface and is also sometimes referred to as a SCOBY. Either samples of this pellicle or unpasteurized kombucha can be used similarly to mother of vinegar to begin fermentation in pasteurized sweet tea.^[1] Referring to the cultures as a "colony" is misleading, because the term colony implies a group of genetically identical or nearly identical organisms living together. The species comprising the mixed cultures vary from preparation to preparation, but generally include Acetobacter bacterial species, as well as various Saccharomyces and other yeast types. SCOBY cultures used in beverage production can produce a structure referred to as a "mushroom," which is also biologically misleading, because mushrooms are a completely unrelated group of fungi. It often forms in vinegar in jars of pickled foods.

Use in food production

Other foods and beverages which require a similar "symbiotic culture" in their production include:

• Ginger beer.
• Kefir, both milk kefir and water kefir (tibicos), whose required cultures differ.
• Jun, a drink similar to kombucha that grows on honey-sweetened green tea.
• Vinegar, the production of which requires a mother of vinegar.
• Sourdough, derived from a sourdough "starter", flour-water mixture exhibiting growth after adventitious contamination with wild yeasts.

Use in clothing production

Queensland University of Technology and the State Library of Queensland have been using kombucha SCOBY to produce a workable bio-textile, called a "vegan leather".^[2]

See also

• Acetic acid bacteria
• Lactic acid bacteria

References

Further reading

• Program entitled "The Fermentation Revival" on BBC News.
• N. Padilla "do it yourself article in the The Harvard Crimson.

External links

• Purported list of kombucha yeast and bacteria, at "Cultures for Health."