  2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center  |
|
287
Application of biological acidification to improve the quality of wort produced with 20 percent raw barley. R. M. Barta (1), K. Bayer (1), D. L. Goode (2,3), C. I. CLARKE (2,3), and E. K. Arendt (2). (1) Institute of Applied Microbiology, University of Agricultural Sciences, Vienna, Austria; (2) Department of Food Science, Food Technology and Nutrition; (3) National Food Biotechnology Centre, National University of Ireland, Cork, Ireland.
The brewing industry is always trying to replace malted barley with cheaper cereals without changing the chemical-physical parameters, flavour and processability of beer. Unmalted barley is one possible replacement for malt, but the addition of unmalted cereals can have negative effects on the quality of beer. In this study the influence of biological acidification using Lactobacillus amylovorus in mashes containing 20% raw barley was investigated and compared to (a) mashes acidified with lactic acid, (b) non acidified mashes and (c) a mash with a grist composition of 100% malt. A slightly modified congress mashing program with an increased holding time of 45min at 45 C was chosen. Characteristics of the laboratory scale mashes examined included mash pH, extract, colour, filterability, viscosity, total soluble nitrogen (TSN), free amino nitrogen (FAN), fermentability, beta glucan, zinc, and sugar and amino-acid profiles. The processability as well as the quality characteristics of the biological acidified mash containing 20% unmalted barley compared well to the mashes produced with 100% malt. Differences were found between the mashes acidified with Lactic acid bacteria and the control acidified with Lactic acid. In conclusion it was clearly shown that biological acidification can compensate for the reduced enzymatic activity generated by the use of 20% unmalted as an adjunct for brewing.
Copyright 2001
The American Association of Cereal Chemists