Determination of Yeast Assimilable Nitrogen (YAN) in Kombucha

CDR KombuchaLab: the kombucha analysis system to optimize the production process obtaining results in real time.

The symbiotic culture of acetic and yeast bacteria immersed in the sweetened tea infusion triggers an alcoholic fermentation. This fermentation can be favoured by the presence of assimilable nitrogen (organic and inorganic) which can be added before fermentation starts. The quantity of assimilable nitrogen can also be controlled during the fermentation process itself in order to guarantee a complete evolution of the fermentation avoiding undesired organoleptic deviations in the finished product.

CDR KombuchaLab: Instruments for the determination of YAN 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.

  CDRKombuchaLab for analysis on Kombucha on pruction line
CDR KombuchaLab
CDRKombuchaLab Junior for analysis on Kombucha on pruction lineCDR 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
Yeast Assimilable Nitrogen (YAN)
Configuration with tailored panel of analyses
Simultaneous Sample Analyses 16 3
Multiple Analyses on a Sample si


Test type: End Point.
Time Testing: one test 4 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 .

Calibration Curve

The calibration curve of the CDR KombuchaLab instrument, carried out using the known concentration of isoleucine for the organic nitrogen and ammonium chloride for inorganic nitrogen, confirmed an excellent linearity of the system over the entire measurement range.

Calibration curve of the KonbuchaLab CDR instrument for organic nitrogen in Kombucha, performed using standards of known concentration of isoleucine. R²=0.9911.

Calibration curve of the KonbuchaLab CDR instrument for inorganic nitrogen in Kombucha, performed using standards with known concentration of ammonium chloride. R²=0.9945.

Test Principle

Organic nitrogen (α – amino nitrogen) and inorganic nitrogen (ammonium ion) are determined separately. In the presence of ammonium and NADH the glutamate dehydrogenase (Gl-DH) reacts with α-keto glutarate to form L-glutamic acid and NAD+. The decrease in absorbance, measured at 366 nm (end-point), of the NADH solution is proportional to the quantity of Inorganic Nitrogen present in the sample expressed in mg of N/L.  The Organic Nitrogen (α-amino) reacts in the presence of N-acetyl-L-cysteine with the o-phthalaldehyde forming an isoindolic derivative. The difference in absorbance, measured at 366 nm (end-point) is correlated with the quantity of organic nitrogen expressed in mg of N/L.

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 *300435: 10 tests

Code *300430: 100 tests

The reagents have a shelf-life of 6 months

Processing Sample 

For precise and repeatable analysis, the sample must be degassed with the appropriate ultrasonic bath (code 222062) with the mini-centrifuge (code 222061) to separate the solid particles present in the solution.

Measuring Range

Test Measuring Range Resolution Repeatability
Organic nitrogen 30 - 300 mg/L 1 mg/L 15 mg/L
Inorganic nitrogen 30 - 300 mg/L 1 mg/L 11 mg/L

Reagents developed by CDR S.r.l - Quality System Certified ISO 9001 Ed. 2015 - Certificate n. 9115

Click here for further information on CDR KombuchaLab for Kombucha analysis: Reliable, quick and simple to use, reliable results

Request a Free Quote Now!
With the CDR system, you can perform your tests in total autonomy

Neither skilled staff nor a dedicated external laboratory is needed to use our systems. CDR FoodLab® optimizes traditional testing methods, making them faster and easier, while guaranteeing accuracy standards in line with the reference methods.

Analytical kit

CDR FoodLab® Analysis Systems use disposable pre-vialed reagents specifically developed by the research laboratories of CDR. The use of pre-vialed reagents and the analytical procedures allow:

  • a sample preparation that is quick and easy, when needed at all;
  • making analytical procedures extremely fast and easy;
  • removing all needs for complex calibration procedures.

Reagents come in aluminum packages containing 10 test tubes each to perform 10 tests (or packages for 100 tests containing 10 single packages of 10 test tubes each).

Just a few steps and results are yielded right away

Just a few steps will suffice to carry out your analysis in a rapid way in total autonomy. The system is composed of both the analyzer based on photometric technology and a kit of low toxicity, pre-vialed reagents, developed by CDR.

CDR FoodLab® is cost-effective because it does not require the use of expensive equipment and does not entail maintenance, assistance or calibration costs.
Find out how it works