This method describes how to determine the hectoliter weight of malt.
Barley malt intended for use in beer brewing or elsewhere in the food industry.
The hectoliter weight determines how many kilograms 100 liters of malt weighs. This analysis provides an estimate for the volumetric space required for storage and transport of a lot of malt.
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
Determination of 3-hydroxy-2-butanone (acetoin) in beer.
The method is suitable for beers of brewed to any original gravity or of any alcohol content.
The compound 3-hydroxy-2-butanone (acetoin) is derived from diacetyl and is created through the reductive activity of yeast. One further reaction mechanism for the formation of 3-hydroxy-2-butanone is condensation of both free and activated (bound to thiamine pyrophosphate [TPP]) acetaldehyde.
3-Hydroxybutanone is oxidized to 2,3-butanedione (diacetyl) by iron chloride in the presence of iron sulfate and determined using gas chromatography and the headspace analysis method.
Determination of the total oxygen content (dissolved and in the headspace) in filled containers
The bottled or canned beer is brought to 20 °C and mechanically shaken, thereby achieving equilibrium between the oxygen dissolved in the beer and the oxygen present in the headspace (Henry’s and Dalton’s laws). By directly measuring either the oxygen in the beer or in the headspace, the total oxygen can be calculated through referencing a table of values, which includes the headspace volume as a percentage of the fill volume.
This method describes the general requirements for boiler feed water:
Boiler feed water for use in the production of beer and other foods
The requirements for boiler feed water are detailed in the analysis methods listed below.
A known quantity of an internal standard (n-propanol) is added to the sample, if necessary after dilution.
The sample is equilibrated at a certain temperature in a headspace vial and part of the headspace is injected into a gas chromatograph.
The ethanol contained is separated on a polar gas chromatography column and detected with a flame ionization detector (FID).
The ethanol concentration in % vol. is calculated from the ratio of the area of the ethanol peak to the area of the internal standard (n-propanol) with the ratios of the same peaks determined when analyzing standards with known ethanol concentrations.