This method describes how to determine the pH of boiler feed water using a universal indicator.
The pH value of boiler feed water is determined using a universal indicator.
The method is suitable for the determination of steam-volatile aging indicators in beer.
Volatile aging indicator substances are driven out of the sample through steam distillation. The ethanol distillate is adjusted to be alkaline and saturated with NaCl. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging. The organic phase is further concentrated in a stream of nitrogen gas. Ammonia solution is added to remove the acids, as the acids would coelute, thus preventing the quantification of important substances.
Pour-plate method and microscopy.
Determining the standard of hygiene through rinse water checks
Macroscopic counting of the colonies formed, microscopy for bacteria, yeasts, moulds
Check for microbiological vulnerabilities by detecting bacteria (moderately acid-tolerant bacteria) and yeasts in process water.
Pour-plate method and membrane filtration
Wort samples of all kinds.
Analysis of wort for beer-spoilage bacteria (anaerobic). In the case of trace infections, it may be necessary to carry out a second enrichment. Slow-growing (e.g. Pediococcus spp.) or thermally damaged microorganisms can also be detected here.