Improving Resistance to Aging and Increasing Haze Stability in Southern German Wheat Beer Through Process Optimization

Roland Feilner (1) and Friedrich Felix Jacob (2). 1. Krones AG, Neutraubling, Germany. 2. Familienbrauerei Jacob oHG, Bodenwöhr, Germany.
Flash pasteurizing beer not only stabilizes it microbiologically but the process also has a favorable influence on the aroma and flavor of the beer. Changes in the sensory profile of the beer occur to a greater degree at the start of the aging process. These changes are perceived as particularly negative by consumers who only purchased the beer a short time before. The primary reason for customer dissatisfaction with beer they have purchased is not that the beer becomes unpalatable before the expiration date, but rather the last bottle in the case does not taste like the first. This situation can be remedied through utilization of a flash pasteurizer, if the concentration of yeast cells in the beer entering the pasteurizer does not exceed a certain level. Although the conversion reactions occurring at temperatures from 60 to 80°C for 30 s during pasteurization do, in fact, result in a certain amount of forced aging, this does not necessarily mean that it will have a negative effect on the sensorial attributes. The use of a flash pasteurizer is especially advantageous in the production of cloudy Southern German–style wheat beer, otherwise known as Weißbier. The stability of a permanent (protein) haze is a key characteristic of cloudy German-style wheat beers. A stabilizing effect can be achieved by shifting the particle size to between 200 and 1,000 nm through thermal agglomeration. The sensory attributes and the energy usage are both positively impacted by reducing the thermal stress, owing to shorter boiling times, thus resulting in further advantages.

Keywords: Southern German-style wheat beer, Turbidity, Colloidal stability, Haze stability, Flavor stability, Flash pasteurizer