Brewery yeast culture, pitching and harvest yeast as well as pure yeast.
Thermally extracted yeasts release their cell contents into the surrounding medium (= yeast water), which is then available for bacteria.
Exclusion of contamination (indirect, potential and obligate beer-spoilage organisms) in the cold wort area.
Pitching wort with pure yeast culture.
In all brewery microbiological tests, the main aim is to detect obligate beer-spoilage organisms, but also potential beer-spoilage organisms that can lead to spoilage of the beverage.
Analysis of wort for beer-spoilage bacteria (anaerobic with pure yeast culture and enrichment).
Detection of harmful yeasts and bacteria in weakly acidic non-alcoholic beverages using liquid pre-enrichment and pouring plate
All non-alcoholic drinks with a pH value > 4.3.
Detection of harmful yeasts and bacteria using liquid enrichment and pour plates.
Detection of harmful yeasts and bacteria in cloudy non-alcoholic beverages.
All cloudy, non-filterable, non-alcoholic drinks with a pH value < 4.3.
For cloudy, non-filterable, non-alcoholic beverages such as juices, nectars, fruit juice drinks and lemonades, the relevant beverage spoilers (in particular fermentable yeasts, respiratory yeasts, lactic and acetic acid bacteria) should be detected in accordance with the methods:
Anaerobic incubation is recommended for carbonated beverages in order to increase the selectivity of the analysis for this type of beverage.
Quantitative detection of harmful yeasts and bacteria in clear, non-alcoholic beverages.
All clear non-alcoholic drinks with a pH value < 4.3.
Detection of harmful yeasts and bacteria using the pour-plate method.
Quantitative detection of harmful yeasts and bacteria in clear non-alcoholic beverages.
All clear, non-alcoholic drinks with a pH value < 4.3.
Detection of harmful yeasts and bacteria using membrane filtration.