Optimised processing of faba bean (Vicia faba L.) kernels as a brewing adjunct

Pulse (Fabaceae) grains, such as peas and beans, are derived from crops that are usually cultivated in the absence of synthetic (mineral) nitrogen fertiliser as these crop types can attain their entire nitrogen requirement naturally from the air via biological nitrogen fixation. Therefore, pulses present a significantly lower greenhouse gas (GHG) footprint than crops demanding nitrogen fertiliser, whilst also offering significant quantities of starch for the brewing and distilling industries. Mitigation of agriculture-derived GHG emissions through utilisation of pulses can have a positive environmental impact. Towards this end, we assessed the potential of exploiting dry, dehulled faba bean (Vicia faba L.) kernel flour as an adjunct for beer production. The impact of different temperature regimes and commercial enzymes were assessed for their effect on wort: viscosity; run-off rate; primary amino nitrogen content; and, fermentability. Faba beans demonstrated insufficient endogenous enzyme capacity for starch conversion and generated a viscous wort. However, using a stepped mashing temperature regime and exogenous enzyme additions, the faba bean wort was comparable in processability and fermentability to that of 100 % malted barley wort. The faba-based beer and co-product qualities demonstrate the environmental, nutritional and commercial potential of pulses in brewing.