Determination of Alcohol Content in Kombucha

The symbiotic culture of acetic bacteria and yeasts immersed in the sweetened tea infusion triggers an alcoholic fermentation that can bring about variable alcohol concentrations from traces by approximately one percentage point. Normally the majority of Kombuchas on the market have an alcohol content that is below 0.5%.  The measurement of this parameter is very important for legal purposes as a concentration above 1.2% requires registration of the beverage produced as “alcoholic”. 

The high power and sensitivity of the CDR KombuchaLab reading cell allows to carry out the analysis of the alcohol content with excellent precision and accuracy both for values lower than 1.8% vol and for values up to 10% vol typical of the "hard kombucha".


Test Principle

Ethanol, in the presence of NAD+ , is oxidized by enzymatic route to acetaldehyde with the consequent production of NADH. The increase in absorbance, measured at 366 nm at the end-point, is directly proportional to the concentration of ethanol in the sample. The result is expressed in %v/v.

Correlation curve

The calibration curve of the CDR KombuchaLab  instrument, obtained by comparing the CDR method with the distillation method for determination of the alcohol content, confirmed an excellent linearity of the system over the entire measurement range.

Calibration curve of the CDR KombuchaLab instrument, obtained by comparing the CDR method with the distillation method for determining the alcohol content. R² = 0.9959

Reagent test Kits

Measuring range

AnalysesMeasuring rangeResolutionRepeatability

The Analyzers for process and quality control in kombucha brewing


CDR KombuchaLab

  • Complete analysis panel, supplied already configured
  • Up to 16 determinations simultaneously
  • Possibility of carrying out analyses of the same sample
  • Integrated printer
  • Full connections (LAN - USB - Bluetooth barcode/QR code reader)

CDR KombuchaLab Jr

  • Partial analysis panel, supplied configured with 3 analyses of your choice, implementable
  • Up to 3 determinations simultaneously
  • Wireless connection to external printer
  • USB connections