Study of Energy-saving Wort Boiling Systems for Czech Beer Production
Keywords:beer quality, bitter acids, boiling systems, sensory active volatiles, wort boiling
The effects of a low-pressure and dynamic low-pressure wort boiling systems on a brewing process economy and quality of the Czech beer were studied in a pilot scale trial brews (200 L) of pale lager beer, that had been prepared in agreement with Protected Geographical Indication Czech beer. The process parameters of brews were designed to make conversion of hop α-acids and thermal charge of wort in low-pressure and atmospheric wortboiling comparable. Despite the balance-reduced boiling time and equal iso-α-acids content in worts, low-pressure wort boiling systems showed increasing yield of iso-α-acids in beer in a series of atmospherics, dynamic low-pressure and low-pressure wort boiling. Conversely to that, head retention decreased in this order. Low-pressure boiling saved significant amount of time and energy (28% and 25%), but sensorial quality of produced beer was significantly different (evaluated as less pleasant), compared to the classical atmospheric boiling system. Beers prepared with the use of dynamic low-pressure and atmospheric boiling have not been distinguished by triangle test. This technology can save a considerable amount of time and energy (approximately 22% and 15%).This article presents the results of the basic pilot study, which will be verified and extended in the further work on this issue.