Preliminary Research on the Analytical and Volatile Profiles of Beers Produced with Raw Malt and Roasted Specialty Malts

Abstract

Preliminary research was conducted on the analytical and flavor profiles of beers brewed (small-scale) with roasted specialty malts and raw malts as adjuncts. Beers were characterized by physico-chemical, sensory, and GC-MS analysis. From the beers produced, 79 volatile compounds were identified, and these were grouped into different categories. Alcohols and esters were found to be the most prevalent volatile compounds in the beers. Principal component analysis, as well as cluster analysis, was applied in order to investigate the similarities and distinctions between the various types of adjuncts and no adjunct beers. The volatile chemicals present in the beers showed that the nature and quantity of these compounds would have an effect on the flavor and quality of the beers. Beers prepared with the roasted wheat malt addition were characterized by the highest number of volatile compounds. Moreover, the beers with roasted wheat malt addition were characterized by higher bitterness (higher than the control beer), high antioxidant activity (equal to the control beer), and a high tannin content (but less than the control beer). Beers were evaluated by a sensory panel that concluded that the adjunct beers had a preferred flavor to the beers without adjunct addition. The highest-rated beer in the appearance, flavor, mouthfeel, and overall acceptability criteria was the adjunct beer with roasted wheat malt incorporated. This preliminary experimentation will help guide where future research is needed and where scale-up experiments with trained taste panels should focus.