Determination of FAN in beer and wort
Free Amino Nitrogen by OPA (FAN) is a test that allows to manage correctly the alcohol fermentation. In fact the lack of Nitrogen can cause a slowing-down or even the stop of the fermentation, compromising seriously the quality and the organoleptic characteristics of the beer. FAN by OPA is a parameter consisting in two shares, Inorganic Nitrogen present in the wort as ammonium ion and Organic Nitrogen present in α-amino form (amino acids). FAN by OPA analysis with the CDR BeerLab® method allows to determine the concentration of the two components separately, giving the possibility to carry out with accuracy the appropriate corrections before and during the alcohol fermentation. The kit for the Inorganic Nitrogen is selective for the ammonium ion and allows to adjust with accuracy a possible addition of sulfate/hydrogen-ammonium phosphate in the wort.
The systems to test Yeast Assimilable Nitrogen (FAN) in beer and wort
 CDR BEERLAB® |  CDR BEERLAB® JUNIOR | |
|---|---|---|
| Analyses | Beer and Wort: Water: | Beer and Wort: |
| Simultaneous Sample Analyses | 16 | 3 |
| Multiple Analyses on a Sample |  | – |
Method
Test type: End Point.
Time testing: one test 4 minutes.
Are possible test sessions with several samples, up to 16 tests for CDR BeerLab® and 3 tests for CDR BeerLab® Junior.
Test Principle
Inorganic Nitrogen – Ammonium through enzyme reacts with NADH α-ketoglutarate giving NAD+ and glutamate. The absorbance decrease of NADH solution, measured at 366 nm, is proportional to the quantity of amine Nitrogen present in the sample.
Organic Nitrogen – The α-amino Nitrogen reacts in presence of N-acetyl-L-cysteine with o-phthalaldehyde forming an isoindole derived. The difference of absorbance, measured at 366 nm (end point), is correlated with the quantity of Organic Nitrogen expressed in mg/L of Nitrogen.
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 *300785 – The kit, designed for 10 tests
- Code *300780 – The kit, designed for 100 tests
The reagents have a shelf-life of 6 months.
Processing – Sample Volume – Measuring Range
Use on wort. For higher accuracy in the analysis of wort we recommend to centrifuge the sample.
| Analysis | Measuring range | Sample volume | Resolution | Repeatability |
|---|---|---|---|---|
| FAN by OPA | 30 – 300 (mg/L of norganic N) | 20 μL | 1 ppm | 2 ppm |
