The method is suitable for the determination of water vapor volatile aroma compounds in beer.
Volatile aroma compounds are driven out of the sample through steam distillation. The ethanolic distillate is saturated with NaCl. Potassium hydrogen sulfite is added to separate carbonyl groups that might interfere with the analysis. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging.
The method is suitable for beers of all original gravities and of any alcohol content.
The gas chromatography headspace method is used to determine the higher alcohols and esters present in beer, i.e., the volatile compounds are transferred from the headspace in the sample vial into the GC system for analysis. The following substances are measured in this analysis:
Acetaldehyde
Propanol-1
Ethyl acetate
2-Methylpropanol
3-Methylbutanol
2-Methylbutanol
2-Methylpropylacetate
Butyric acid ethyl ester
3-Methylbutyl acetate
2-Methylbutyl acetate
Hexanoic acid ethyl ester
This method is suitable for the determination of steam-volatile aroma compounds in wort.
Volatile aroma compounds are driven out of the sample through steam distillation. The ethanol distillate is adjusted to be alkaline and saturated with NaCl. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging. The organic phase is further concentrated in a stream of nitrogen gas. An ammonia solution is added to remove the acids, because the acids would co-elute, thus preventing quantification of the target substances.
Whole hops intended for use in beer brewing or elsewhere in the food industry
Evaluation of the appearance of hop cones is performed through visual inspection and sensory assessment.
Determination of xanthohumol and isoxanthohumol
All beers, beer-based beverages, wort, ethanol extracts, CO2 spent hops and xanthohumol products
Xanthohumol and isoxanthohumol are dissolved with acetonitrile from the sample and following separation, are determined using a Nucleodur C18 column and UV detection.
Determination of the vicinal diketone content (diacetyl + 2,3-pentanedione) as well as the total diketone content in beer
The method is suitable for filtered beers brewed to any original wort or to any alcohol content as well as for fermenting wort.
Diacetyl (2,3-butanedione) and 2,3-pentanedione are detected photometrically in the beer after steam distillation. It is also possible to determine precursors in green beer.