Did you know the heart of our brewery in Plzeň is underground? In 1842 we started lagering our golden lager in oak barrels in the labyrinth of cellars under the brewery. The cold temperatures down there are ideal for bottom fermentation.
But when the brewery was modernised in 1992 and we installed new technology, we started fermenting and lagering most of our beer in stainless steel tanks above ground. This meant we could more precisely control the process, like the temperature and the amount of yeast we add.
Of course, we were worried this change might affect the flavour of our beer – we’re always worried about that! So a team led by Václav Berka, our Brewmaster, decided that we should continue to brew a small portion of our beer in the cellars – that way it could be compared with the beer made in the new tanks. We called this parallel brewing.
The process involves us brewing beer the same way we always have, and then getting a team of current and retired Brewmasters, as well as the brewery’s own tasting panel, to conduct comparative taste tests in the laboratory. The objective is for the expert team not to taste any differences between the two – that way we can be sure we’ve kept the quality consistent. After all, the point of technology isn’t to change the taste of the beer, but to improve the efficiency of making it.
It took a few batches of tasting and testing before the modern tanks could perfectly replicate the unique flavour of our golden lager so the Brewmasters couldn’t tell whether the beer came from the new or the old vats. We even brought in a few Brewmasters who had long since retired to help shape the future of Pilsner Urquell’s brewing process.
And today, even though we know the modern tanks make great beer, we still insist on parallel brewing. It’s our historic marker – a way of honouring our past, never forgetting our traditions and constantly checking the future of our beer. Other breweries would never parallel brew because it takes too much time and costs too much, but the most important thing for us is the flavour of our beer!