Preparation of specialty malt via microwave processing

Abstract

The burgeoning craft beer market fuels demand for specialty malts, yet conventional production in roasting drums is energy-intensive and inefficient. This study developed an approach to producing specialty barley and wheat malts using microwave processing with a tumbling step to ensure homogeneity. The resulting malts exhibited significantly darkened colour, enhanced antioxidant capacity, and increased total polyphenol content. Analysis of volatile compounds revealed the generation of characteristic roasty pyrazines and caramel-like furans. When used in brewing (15 % substitution), these malts influenced the beer profile, intensifying colour, increasing perceived bitterness, and reconstituting the aroma by suppressing base malt notes and enhancing roasted attributes. Our results demonstrate that microwave processing is an efficient method for processing specialty malts.