In the lab of the Plzeňský Prazdroj brewing company, the raw ingredients barley, hops, and water are tested, and so is the finished product itself at each step of the production process. The brewers also feel responsible for the unique flavor of their beers such as Pilsner Urquell and Gambrinus — right up to the moment it flows from the tap. Company employees regularly check the cleanliness of the tap systems in order to ensure that guests enjoy the full taste experience. “For this job the brewery uses the HY-LiTE devices we developed,” explains Mirka Řehořová, a Merck employee in the Czech Republic.

This luminometer analyzes the ATP (adenosine triphosphate) content in a sample. ATP, as the energy carrier of all biological cells, is a stable molecule and is therefore best suited for indicating the presence of biological material in a sample. The ATP content is confirmed by means of bioluminescence, which is also how fireflies produce light, for example. The enzyme catalytic reaction of ATP releases energy that is radiated as light. Its intensity is measured in “relative light units” (RLUs) by means of a detector. The RLUs, in turn, are linked to the biological cell content of the sample. “Interpreting these values requires a certain level of experience,” Řehořová, a chemist, explains, “because you have to take into account the varying basic content of ATP that is already present due to the nature of the individual types of beer.”

The brewery conducts this test solely to ensure the beer’s hygiene, which can be affected or even become a cause for concern before the sensory quality changes. The benefit of the HY-Lite method is that these adverse effects on hygiene can be clearly identified very quickly — within five minutes. This enables the brewers, and the pubs and restaurants that serve the beer, to promptly take the appropriate measures to ensure that they can offer their customers beer of consistently high quality.