Incorporating crop rotation and malted faba beans to enhance beer sustainability

Why was the work done: The brewing industry faces growing challenges from stricter regulations and from climate change, driving the need for sustainable innovation. One approach is the use of legumes as brewing adjuncts, given their low carbon footprint and ability to fix atmospheric nitrogen in soil. Incorporating diverse crops, such as barley, wheat, oats, and faba bean, promotes regenerative agriculture but also broadens raw material use in brewing. With the aim of promoting regenerative agriculture and sustainability in brewing, this study explores a ‘crop rotation’ beer made from barley, wheat, oats, and faba bean. How was the work done: The use of malt bills including barley, wheat, oats, and faba bean would support crop rotation and diversify raw materials. Faba bean was incorporated in both a raw and malted form. Brewing was performed at both laboratory and pilot scale, and the physicochemical and sensory properties of the beers were evaluated in comparison to barley malt beers. What are the main findings: The results show that crop rotation worts made with malted faba beans (Sprau®) were superior to raw faba beans with improved maltose levels, greater free amino nitrogen, and more protein, alongside lower polyphenol concentration. Further, pilot scale crop rotation beers brewed with Sprau® and its starch fraction achieved a more balanced flavour profile and higher ratings for taste, aroma, and overall quality, compared to those brewed with raw faba beans. The quality scores of the beers containing Sprau® were considered 'good' (>6) and on par with those observed with commercial malted barley beer. Why is the work important: A ‘crop rotation’ beer, utilising malt made from four different crops, can be produced with similar physicochemical and sensory properties to beer from malted barley. Incorporating legumes in the malt bill supports sustainable farming practices, enhances biodiversity, and reduces reliance on cereal grains such as barley. Compared to raw faba beans, malted faba beans (Sprau®) exhibited superior physicochemical, functional, and sensorial properties, making them more suitable for brewing application. Therefore, incorporating malted legumes can yield beers with a balanced flavour profile and this offers brewers new alternatives for improving the sustainability of their products.