Quantitative Determination of Ethyl Alcohol in Kombucha Using an Inexpensive Sensing Device

Kombucha, a popular probiotic beverage, contains detectable concentrations of ethyl alcohol. To be sold as a nonalcoholic product, alcohol concentrations in kombucha must be shown to be less than 0.5% by volume. This paper describes the use of an inexpensive, commercially available sensor to reliably and accurately measure alcohol concentrations in kombucha across a variety of undergraduate chemistry laboratory courses. Procedures and assessment data are also provided for two courses: an introductory course for nonchemistry majors and upper-division analytical chemistry. In the case of the analytical chemistry course, results from the alcohol sensor were compared to headspace gas chromatography as a capstone assessment. In all cases, the alcohol content of multiple commercial kombucha samples were determined, and students submitted final reports using appropriate scientific writing aligned with precise learning objectives.

Automated summary

This paper describes the use of an inexpensive, commercially available sensor to reliably and accurately measure alcohol concentrations in kombucha across a variety of undergraduate chemistry laboratory courses. Procedures and assessment data are also provided for two courses: an introductory course for nonchemistry majors and upper-division analytical chemistry. The alcohol content of multiple commercial kombucha samples were determined, and students submitted final reports using appropriate scientific writing aligned with precise learning objectives.