Environmental impact assessment of dairy protein from precision fermentation

Abstract Purpose Precision fermentation (PF) has emerged as a promising approach to produce animal-free dairy proteins, yet its environmental performance remains insufficiently understood, particularly for consumer-ready products. This study quantifies the environmental impacts of a PF–based milk-like beverage (PF milk) in different scenarios and compares its impacts with cow’s milk and an oat-based drink. Results are reported per kilogram of final product at the point of consumption and per kilogram of protein powder (92% purity). Methods A cradle-to-consumer comparative LCA was conducted according to ISO 14040 in openLCA 2.4.1, comparing PF milk produced with recombinant beta-lactoglobulin, cow’s milk, and an oat-based drink. Impact assessment was based on EF 3.1, complemented by a biodiversity indicator linked to land use. Five electricity scenarios (European average, German, Polish, Norwegian, and 100% renewable) and two process-improvement scenarios were modelled. Comparative results across all scenarios are shown relative to cow’s milk. Results Climate impacts of PF milk range from 0.64 kg CO 2 -eq/kg under low-carbon electricity to 1.29 kg CO 2 -eq/kg under fossil-intensive electricity mixes leading to a reduction of 10–55% compared to cow’s milk (1.44 kg CO 2 -eq/kg). Under the European average electricity mix, PF milk results in 0.86 kg CO 2 -eq/kg, which is 40% lower than cow’s milk and 76% higher than the oat-based drink (0.49 kg CO 2 -eq/kg). Fossil resource use of PF milk exceeds oat-based drink (7.52 MJ/kg) and cow’s milk (6.94 MJ/kg) across all scenarios, ranging from 8.09 to 15.57 MJ/kg (+ 17%–124% relative to cow’s milk). This is mainly driven by electricity demand during protein production and fossil resource use associated with formulation, packaging, and distribution. Compared to cow’s milk, land occupation is reduced by 60–68% and biodiversity impacts by 45–51%, largely irrespective of the electricity mix. Conversely, PF milk exhibits higher water-related impacts than both reference products in all scenarios, with volumetric water use exceeding cow’s milk by 402–878% (0.15–0.3 m³/kg) and scarcity-weighted water use by 65–354% (0.62–1.72 m³ world-eq/kg). Conclusions Electricity supply, feedstock sourcing, formulation, and downstream logistics dominate the environmental performance of PF milk. PF milk substantially reduces land use and biodiversity pressures relative to dairy, whereas climate, fossil resource use, and water use impacts remain highly dependent on energy supply and process conditions. PF milk is thus best regarded as a context-specific complement to plant-based alternatives rather than a universal solution for sustainable food systems.