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.
Detection of harmful yeasts and bacteria using liquid enrichment.
All non-filterable concentrates, bases and syrups.
A defined portion of the sample is mixed with culture medium (SSL broth), incubated and analysed.
Detection of harmful yeasts and bacteria by means of liquid enrichment.
All cloudy beer-based beverages and lemonades.
A defined portion of the sample is mixed with the culture medium (SSL broth), incubated and analysed.
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.
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.
Cloudy beer samples with sediment
Microscopic examination of the sediment for obligate beer-spoilage organisms and wild yeasts by selective enrichment.