Rapid assessment of the risk for microbiological spoilage of packaged beer. Descriptors: ATP Analysis of Final Product, ATP content, free ATP, bioluminescence method, ATPase, extracellular ATP, RLU values.
Differentiation of Gram positive and Gram negative bacteria. Descriptors: Gram Staining for Differentiation of Bacteria, cell wall structure, crystal violet dye, red saffranin.
Rapid differentiation of Gram positive and Gram negative bacteria. Descriptors: KOH Method for Gram Differentiation.
Differentiation of catalase positive and catalase negative bacteria. Descriptors: Catalase Test, enzyme catalase, decompose hydrogen peroxide (H2O2) into H2O and O2.
Differentiation of oxidase positive and oxidase negative bacteria. Descriptors: Oxidase Test, tetramethyl-p-phenylene diamine, enzyme oxidase.
Yeasts isolated on agar plates can be checked for spoilage potential by their ability to decarboxylate an organic acid, producing a distinctive odour. This method, originally described by EBC, was adopted by the ASBC as an international method in 2016 / 2017 and reciprocated as an international method by EBC under the same number in 2018. Descriptors: Phenolic Off Flavour (POF), decarboxylate ferulic acid to 4-vinyl guaiacol, aroma of cloves.
Descriptors: Identification of colonies (bacteria or yeasts) from agar plates or membrane filters by their capability to catabolise different nutrients.
It is necessary to use EBC Microbiology 2.3.3.3
Analysis of turbid samples (enrichments or yeast containing) and of colonies from agar plates for the presence and identification of bacteria, yeasts and/or moulds by detection of their DNA (deoxyribonucleic acid). Descriptors: Detection and Identification of Microorganisms from Turbid Liquid.
It is necessary to use EBC Microbiology 2.3.9.1 to 2.3.9.5
Analysis of filterable samples for the presence and identification of bacteria, yeasts and/or moulds by detection of their DNA (deoxyribonucleic acid). Descriptors: Detection and Identification of Microorganisms from Filterable Samples by Real-Time PCR (Polymerase Chain Reaction), PCR analysis, DNA Extraction, PCR thermocycling instrument, specific primers and probes systems in PCR, lysis buffer, DNA polymerase (usually TaqPolymerase), RealTime PCR thermocycling instrument, Real Time PCR, ready-to-use DNA extraction kits and PCR applications.
It is necessary to use EBC Microbiology 2.3.2.1 and 2.3.9.1 to 2.3.9.5
Descriptors: Identification of colonies (bacteria, yeasts and/or moulds) from agar plates or membrane filters by specific detection of their DNA (deoxyribonucleic acid).
In trouble shooting and tracing of contamination routes, identification below the species level is often useful. Ribotyping is a DNA fingerprinting technique enabling the discrimination of bacterial strains within the same species from each other. Species identification can be achieved at the same time, if a relevant ribopattern identification database is available. Descriptors: Bacteria Ribotyping, restriction fragment length polymorphism analysis, restriction enzymes, fingerprints (ribopatterns).
It is necessary to use EBC Microbiology 2.3.3.3
Determination of the yeast cell concentration in stored pitching yeast, fermenting or stored beer. Descriptors: Haemocytometry, counting chamber, counting chambers (Thoma, Malassez, Bürker-Türk, Neubauer), counting area.
Instrumental determination of the yeast cell concentration in fermenting beer or pitching yeast. Descriptors: Electronic Counter, modifies the resistance between the electrodes, electrolyte.
Determination of the yeast cell concentration of stored pitching yeast, fermenting or stored beer with counts over 1 million cells per ml. A concentration step is necessary for samples containing less than 1 million cells. Descriptors: Photometric Determination, photometer, calibration curves.
It is necessary to use EBC Microbiology 3.1.1.1 or 3.1.2.2
Instrumental determination of yeast cell concentration and yeast viability in brewing yeast containing samples.
Procedures to be employed for obtaining representative samples of barley for analytical purposes. Descriptors: cylindrical sampler, divided sampling spear, dynamic sack sampling spear, cargo sampler, pelican sampler, ellis cup sampler, typical automatic sampler for conveyor belt and conveyor belt discharge, diverter type sampler, hand-scoop, quartering irons, conical divider, sample divider, schedule for sampling cereals
The rapid estimation of yeast fraction in a slurry. Descriptors: Centrifugation of yeast mass, alkaline treatment.
Determination of the concentration of yeast in suspension by means of its dry weight. Descriptors: Dry Weight of Yeast, centrifugation, alkaline solution.
Rapid estimation of the percentage of “viable” yeast cells by counting dead cells. The method is applicable to all samples containing yeast. Descriptors: Methylene Blue / Violet Stain, ratio between total and dead cells.
Rapid estimation of the percentage of “viable” yeast cells by counting dead cells. Descriptors: Fluorescence Stain for yeast analysis, fluoresce under UV-light, percentage of fluorescing cells.
Estimation of the percentage of viable cells capable of reproducing in a yeast sample. Descriptors: Slide culture techniques for yeast analysis, micro-colonies.
The determination of the moisture content of barley by loss of mass on drying under conditions specified in the ISO Method for moisture content of grain (ISO 712-1985).
It is necessary to use EBC Methods 1.1 and 3.1
Primary differentiation of yeasts based on cell morphology. Descriptors: cell morphology of yeasts, size, shape, vegetative reproduction of the cells, examine only pure cultures.
The determination of the total nitrogen content of barley by a Kjeldahl procedure.
It is necessary to use EBC Method 3.1 and 3.2
Quantitative estimate of the proportions of the different brewing yeast strains present in a mixed culture. Descriptors: cell colony morphologie, yeast giant colonies, long-time incubation.
The method is intended for breweries that use different yeast strains in fermentation. lt may give a quantitative estimate of the proportions of the different strains present in a mixed culture depending on the strains. Descriptors: yeast morphology on WLN agar.
The determination of the total nitrogen content of barley by a combustion method based on the Dumas-principle.
It is necessary to use EBC Method 1.1, 3.1 and 3.2
The laboratory storage of brewing yeast stocks cultures over a number of years. It has been demonstrated that the genetic stability and survival of brewing yeast strains are optimal after cryopreservation at ultra-low temperatures (below -139 °C) compared to other preservation methods. The cultures may be stored in plastic tubes or straws. The present method describes the preservation in polypropylene straws under liquid nitrogen or in mechanical freezers. Descriptors: yeast storage at ultra-low temperatures, cryoprotectant agent, long-term storage, cryopreservation, dehydration, osmotic imbalance, intracellular ice.
This method describes the storage of brewing yeast strains for short periods of time (up to 6 months) in the laboratory. Changes in brewing yeast genotype following maintenance of the strains by repeated subculturing have been reported to influence yeast brewing performance. Preservation of the original properties of the stored yeasts in the long term is only recommended at ultra-low temperatures. For short-term storage (up to 6 months), other methods are available that allow safe and simple management of strains in the lab. Repeated subculturing for preservation of brewing yeast should be totally avoided. Descriptors: yeast subculturing for short-term storage.
It is necessary to use EBC Microbology 3.4.1
The shipment of brewing yeast strains from a supplier laboratory to a receiving laboratory where they are to be propagated for industrial purposes. Descriptors: yeast strain transport, short-term storage, free from contaminant microorganisms.
It is necessary to use EBC Microbiology 3.4.2
