Most food manufacturers in industrialised countries produce significant amounts of food waste during their manufacturing activities. Due to the serious environmental consequences of managing these materials, environmental impact analyses have become popular to identify more sustainable practices for food waste management. Life-Cycle Assessment (LCA) is a useful methodology to assess such environmental impacts. This paper presents the main results obtained using the LCA methodology to analyse the potential environmental impacts of waste management for a brewery in the UK. Initially, the main waste types are identified for this industry: barley straw, malt waste and spent grain, and then barley straw is selected to study its environemental impact in detail. An alternative, more sustainable way to manage barley straw by extracting its wax with supercritical CO2 is discussed. SimaPro software is used to both quantify potential environmental impacts and evaluate the overall environmental performance of this valorisation opportunity, and to compare its modelled environmental impacts to the current impacts of managing barley straw. Results show that valorising barley straw by this method generates a high environmental impact due to the energy requirements of the processes involved, principally for human toxicity (cancer effects), human toxicity (non-cancer effects) and freshwater ecotoxicity impact categories. Using more energy-efficient processes or an alternative energy source would reduce this environmental impact. The analysis used in this paper allows an objective comparison between different scenarios with the final aim of supporting the use of sustainable solutions for waste management in the food industry.