Part II. The use of malt produced with 70% less malting loss for beer production: Impact on processability and final quality

Good modification of malt is of crucial importance in terms of its processability in the brewing process. Conducting modification in malting is always accompanied by increasing malting losses. In a previous work, we were able to produce malts with significantly lower malting loss (Lactobacillus plantarum AB1 [AB1] malt and chemically acidified solution [CAS] malt) but also with less modification than control malt (CS malt). Laboratory-mashing trials with both AB1 malt and CS malt were conducted to determine whether reduced malt quality could be compensated for. Response surface methodology was applied to determine the relative contributions of the temperature-rest duration at 45, 50, and 62°C in a successive mashing regime on the quality of wort. Quality characteristics of wort were statistically evaluated and mathematical models created. The most accurate models were applied to design mashing regimes for both AB1 and CS malts with the aim of producing worts with similar and sufficient quality parameters. The mashing regimes were successfully transferred to a pilot-scale plant. The models obtained for AB1 malt suggested extended temperature rests at 50 and 62°C of 31.1 and 32.2 min, respectively, when compared with the mashing regime calculated for CS malt. The application of the proposed mashing regimes resulted in similar amounts of β-glucan in CS and AB1 worts and slightly lower viscosity levels in the latter. Soluble nitrogen could be increased by extended mashing times, but α-amino nitrogen was not affected. The reduced modification of malt interfered with solubilization and enzymatic degradation of starch and could be improved but not totally compensated for by adequate mashing. Pilot-scale brewing revealed that no major problems have to be expected in terms of processability. Significantly diminished fermentation performance in terms of final attenuation was observed for wort produced from AB1 malt. Sensory quality of all fresh beers was comparable. This article demonstrates that malts produced with significant reduction of malting loss can be used to produce wort and beer with sufficient quality.