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”. There are also products called “hard kombucha”, with a higher alcohol concentration.
CDR KombuchaLab: Instruments for the determination of Alcohol by Volume in Kombucha
The instruments are supplied pre-calibrated and ready to use.
The results are expressed according to the reference method.
The methods are simple: there is no need for an equipped laboratory or for specialist personnel.
 CDR KombuchaLab |
 CDR KombuchaLab Junior |
|
|---|---|---|
| Analyses | Kombucha: Alcohol by Volume Total Polyphenols Fermentable Sugars Acetic Acid Total Acidity Gluconic Acid Galacturonic Acid L-Malic Acid Total Lactic Acid Glycerol Yeast Assimilable Nitrogen (YAN) |
Configuration with tailored panel of analyses |
| Simultaneous Sample Analyses | 16 | 3 |
| Multiple Analyses on a Sample |  |
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Method
Test type: End Point.
Time testing: one test 11 minutes.
Analysis sessions with multiple samples are possible for up to a maximum of 16 tests for CDR KombuchaLab and 3 tests for CDR KombuchaLab Junior .
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.
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 thanol, 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.
Reagent test Kits
The reagents are packaged in foil pouches containing 10 tubes useful to perform 10 analyses.
This is the minimum package that allows the use of CDR systems even to those who need to make a few analyses, thus not wasting reagents.
There are also boxes of 100 tests, however, packaged in 10 bags of 10 tubes containing the reagent.
Code. *301155: 10 tests
Code. *301150: 100 tests (10 packages of 10 tests)
The reagents have a shelf-life of 6 months
In case the method Alcohol Content [0.10 – 1.80] % is selected, use the dilution kits:
Code *300624 – The kit allows 100 dilutions and contains 10 x code *300623.
Code *300623 – The kit allows 10 dilutions.
In case the method Alcohol Content [1.0 – 10.0] % is selected, use the dilution kits:
Code *300629 – The kit allows 100 dilutions and contains 10 x code *300619.
Code *300619 – The kit allows 10 dilutions.
Processing Sample
For precise and repeatable analysis on the must, the sample must be degassed with the appropriate ultrasonic bath and centrifuged (code 222062) with the mini-centrifuge (code 222061) to separate the solid particles present in the solution.
Measuring Range
| Test | Measuring Range | Resolution | Repeatability |
|---|---|---|---|
| Alcohol by volume [0.1-1.8] % | 0.1 - 1.8 %vol | 0.01 %vol | 0.02 %vol |
| Alcohol by volume [1-10] % | 1 - 10 %vol | 0.1 %vol | 0.1 %vol |
