Whole Wheat Bread Improves the Nutritional Composition and Quality of Beer During Long-Term Storage

Beer is one of the most widely consumed alcoholic beverages worldwide, whereas surplus bread constitutes a significant environmental burden; repurposing this bread as a brewing adjunct offers a sustainable mitigation strategy. In this study, we replaced 50% of the malt grist in American Lager, India Pale Ale and Bavarian Weiss with stale whole wheat bread, brewed each beer and its malt control in duplicate, and stored them for 12 months at 15 °C. Bread addition raised turbidity and soluble protein at bottling; however, after 12 months, the bread lagers clarified to 101 NTU while the controls stayed above 600 NTU. Alcohol content, pH and titratable acidity were unaffected. All bread beers retained more total polyphenols and showed stronger DPPH radical-scavenging activity than controls, especially in lager and IPA. Lactobacillus (<100 CFU mL−1) and Enterobacteriaceae (<10 CFU mL−1) remained below detection limits in bread samples, whereas the malt-only Weiss displayed Lactobacillus spoilage. Sensory panels noted fuller body, livelier carbonation and enhanced toasted-malt aroma in bread beers, with no sensory off-flavour defects detected. Repurposing surplus bread therefore improves clarity, preserves bioactive compounds and yields distinctive, shelf-stable beers while advancing circular-economy goals.