Virginia-grown Barley for Craft Brewing: Evaluation of Free Amino Nitrogen Content and Malt Sensory Characteristics

Regionally-Grown barley is in demand for craft malting and brewing in Virginia. Barley lines suited to both Virginia's climate and craft brewing applications are currently under development. Free amino nitrogen (FAN) is a malt quality parameter that influences beer flavor directly and via yeast metabolism during fermentation. FAN and the individual amino acids making up FAN influence yeast health, beer color development, flavor, and flavor stability. Despite potential impacts on beer quality, individual amino acid concentrations in barley and malt are not generally measured or monitored. The objective of this project is to evaluate and assess the conversion of FAN and individual amino acid concentrations during the malting and mashing process of genetically distinct varieties. An additional objective is to evaluate their malt sensory characteristics, to understand genetic variability therein. Raw barley and malt samples were subject to low temperature aqueous extraction, and wort was produced using an isothermal hot water extract technique. FAN and amino acid composition were determined for each line for raw barley, malt and wort extracts, prepared as described. Statistical analysis revealed that these lines had significantly different changes in FAN and amino acid composition. Sensory characteristics of malt hot steep teas were evaluated by forty (N=40) panelists with brewing experience using a sorting task to group malts with similar sensory characteristics, and to assign descriptors to those groups. From the sixteen (N=16) breeding lines, five (5) distinct sensory groups were identified. Taken together, our findings will inform the selection process for barley lines for craft brewing, and add to the knowledge of the extent to which free amino acid composition varies among eastern barley lines and along the malting and mashing processes.