Kombucha

Kombucha is a complex, living product with an enormous range of styles and flavors that delight the senses and enliven the body. Mixed with juice, spices or brewed with other beverages; it is most often consumed raw but can also be filtered, force carbonated or in some cases pasteurized; and it can be fermented with a variety of substrates yielding new and exotic combinations. This amazing diversity of expression is part of the mystique of kombucha but also presents difficulty when testing for ethanol due to its inherent biodiversity and complexity, as well as the wide spectrum of serving possibilities.

Kombucha companies currently rely on individual labs to test for ethanol. The KBI Special Projects Team (sub-committee of LGO) contacted over a dozen labs with experience working with kombucha and discovered that each lab has its own method for testing for ethanol. Three main methods are being utilized for testing ethanol in kombucha – alcolyzer (refraction), densitometry and gas chromatography. Moreover, each lab will apply their own tweaks and adjustments to the process in order to account for kombucha’s unique characteristics. The inconsistency in methodology is concerning because kombucha has so many quirks that need to be accounted for and numerous decisions in the testing process can have a significant effect on the final result. With so many changing the methods ever so slightly, it is little wonder that consistent results are simply not achievable.

Kombucha is fermented tea. Tea and sugar are fermented using a SCOBY (Symbiotic Culture of Bacteria and Yeast) for a period of time to achieve a tangy, naturally effervescent beverage with a host of health properties. Like all fermented foods, Kombucha also produces trace amounts of alcohol from .1-2% ABV depending on several factors such as fermentation time, temperature, flavorings added, and the like.

• Microbiological Testing
  • Bacteria:
    • Lactobacillus group: L. casei, L. paracasei, L. coryniformis, L. rossiae, L. parabuchneri (= frigidus), L. perolens, and L. plantarum
    • Lactobacillus brevis
    • Lactobacillus lindneri
    • Lactobacillus backii
    • Lactobacillus (para)collinoides
    • Lactobacillus acetotolerans
    • Megasphaera spp.
    • Pectinatus spp.
    • Pediococcus spp.
  • Yeast:
    • Saccharomyces spp. (including S. cerevisiae, S. pastorianus, S. cerevisiae var. diastaticus)
    • Brettanomyces / Dekkera spp. (including B. bruxellensis)
    • Candida spp. / Pichia spp.
    • Zygosaccharomyces spp. (including Z. bailii)
    • Saccharomycodes spp.
    • Schizosaccharomyces spp.
• Analytical Analysis:
  • Alcohol by Weight (ABW)
  • Alcohol by Volume (ABV)
  • pH
  • Calories
  • Color
  • CO2
  • Specific Gravity