Product spoilage can be divided into different categories depending on the type of microbiological contamination.
The method describes the harmfulness of microorganisms in beer-based beverages.
The beer-based beverage segment includes beverages with a wide variety of compositions.
Both clear and yeasty beers are used in the mix. The proportion of beer varies between 30 and 90 %. Clear or fruit-flavoured soft drinks are used. Various sweetening components are also used. The pH value of the finished beverage can vary greatly from product to product. These diverse influencing factors have an affect on the microflora, which can negatively impact the respective product.
Table 1 provides an overview of the harmfulness of microorganisms in mixed-beer beverages.
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
A reliable sampling method for whole hops and hop products is a prerequisite for obtaining suitable material for analysis. The effort involved in collecting the sample depends upon how uniform the hop product is.
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
After corn starch is converted through the addition of purified, heat-stable α-amylase during a 15 min boiling process and subsequent Congress mash procedure, the extract content is determined.
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
The respective constituents of hops are not uniformly distributed throughout the cones. The aroma compounds and bitter substances are found in the lupulin glands inside the cone, adhering to the cone bracteoles near the strig. The polyphenols, on the other hand, are found in the bracts, bracteoles and stems. In order to reliably analyze the constituents of hop cones, homogenization of the sample is required. For this purpose, the cones are ground and the sample is divided.
Hop products with isomerized or reduced iso α-acids intended for use in beer brewing or elsewhere in the food industry
Hop products with isomerized or reduced iso α-acids are dissolved with methanol. The bitter acids are separated through reverse phase high-pressure liquid chromatography (RP-HPLC) and isocratic elution. They are then measured at a wavelength of 270 nm.