Mineral, spring and table waters as well as drinking waters that are to be marketed.
Qualitative detection of sulphite-reducing, spore-forming anaerobes in mineral water, spring water, table water, and other drinking water bottled for distribution to the consumer, by means of membrane filtration and immersion of the filter in single-concentrate dextrose-iron citrate-sodium sulphite broth (DRCM broth).
Note 1: If only the spores of sulphite-reducing anaerobes are to be analysed, the prescribed sample volume must be heated at 75 °C ± 1 °C for 10 minutes in order to inactivate the vegetative cells. Then cool quickly with cold water.
Important: Carry out a comparative test with the same volume of tap water to determine the total heating time required in the water bath.
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.
This method is suitable for the determination of anions (chloride, sulfate, nitrate, phosphate) in beer samples and other beverages by means of ion chromatography.
The anions chloride, sulfate, nitrate and phosphate are separated by means of ion chromatography. The conductivity detection with a suppressor provides quantitative information about the anions. The concentrations are calculated by means of the individual areas under the peaks from the chromatogram with reference to calibration factors.
Process samples that contain yeast
Anaerobic cultivation, dark-field microscopy of the sample.
The method describes the conditions for inoculating a culture medium.
Laboratories in the beverage industry in general and the brewing industry in particular.
The removal and addition of material from and to cultures, e.g. when inoculating culture media. Strict care must be taken to ensure that no foreign microorganisms enter the culture vessels or the inoculation material being transferred.
This method describes the determination of four hop aroma compounds found in hops and hop products using gas chromatography.
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
The hop oil obtained through steam distillation (refer to links) is dissolved in an organic solvent, separated into its components by means of gas chromatography and determined with a flame ionization detector. The contents are expressed as a percentage of the area of each component compared to the overall area of the peak.