116. Alcohol-free wheat beer: Optimizing the brewing process and product quality with sour wort

Birgit Schnitzenbaumer (1); (1) Doehler GmbH, Darmstadt, Germany

Enzymes, Extracts, Other Ingredients
Poster

Alcohol-free beer, in particular wheat beer, is a booming beverage category not only in Germany. The popular thirst quencher and healthy sports drink is most commonly produced using the “stopped fermentation” method. However, the so obtained alcohol-free beers often have a non-desirable wort-like character due to the short yeast fermentation time. Nevertheless, their quality and drinkability can be enormously improved by means of biological mash and wort acidification. Within this study, two alcohol-free wheat beers were produced in a medium-sized German brewery: one with sour malt (mash acidification; reference brew), as well as one with sour wort (mash and wort acidification). The pH value of the final alcohol-free beers and all other process parameters were kept constant. It was found that by increasing the mash pH from 4.3 (sour malt brew) to 5.3 (sour wort brew), the brewing process was optimized in terms of extract yield, hop alpha-acid isomerization and lautering performance. Furthermore, the targeted pH adjustment with sour wort before and after wort boiling to 5.1 and 4.6, respectively, resulted in extensively reduced concentrations of aging indicators in both fresh and forced-aged products (sour wort brew). These findings were reflected in the sensory quality of the final alcohol-free wheat beers analyzed according to the DLG scheme (5-point scale; 1 = dislike extremely, 5 = like extremely). Thus, the fresh brew with sour wort received a considerably higher overall score of 4.55 compared to the fresh sour malt brew (4.34). In addition, the use of sour wort in alcohol-free wheat beer production had a clear positive effect on flavor stability.

Birgit Schnitzenbaumer worked full time as an assistant tax consultant before she studied brewing and beverage technology at the Technical University of Munich in Weihenstephan, Germany. She graduated as a Dipl.-Ing. (M.S. degree) in brewing and beverage technology in 2009. Birgit was awarded a full doctoral scholarship by the InBev-Baillet Latour Fund and did her Ph.D. thesis on the application of enzymes when brewing with unmalted oats and sorghum at the University College Cork in Ireland. Since July 2014, Birgit has worked as a product manager for cereal and malt ingredients at Döhler in Darmstadt, Germany.