Volatility of Benzaldehyde in Water/Wort

Abstract

The brewing process defines the final taste of beer, and therefore it is important to minimize unwanted flavor components in the brewing process. The best tool is the boiling process, in which unwanted components are vaporized. Vaporization requires energy, and it is the scope of every new development in the brewhouse to reduce energy and to save money. For reducing and optimizing the vaporization of unwanted flavor components, it is important to understand the thermodynamic behavior of flavors in wort. Each component has its own thermodynamic behavior. This article is about the unwanted flavor benzaldehyde (BENZ). Therefore, its volatility in water/wort at infinite dilution over a broad temperature range (30, 40, 50, 60, 70, 80, and 90°C) is determined. The volatility describes the thermodynamic behavior of a component i soluted in a component j, and as the volatility becomes higher less energy is needed for vaporization. To calculate the needed vaporization energy to reduce the content of BENZ the volatility has to be measured. Therefore, four different and independent measurement methods (recirculating still, Rayleigh distillation, Dohnal method, and flash distillation) were used. The central result of the measurements is that BENZ in water at infinite dilution has a maximum volatility (KBENZ,60° = 42 ± 3) at a temperature of 60°C. Thus, vaporization at this temperature is the most efficient tool to reduce this special flavor component.