Whey2blue, through the upcycling of dairy side streams into microalgae biomass, develops a sustainable, circular and affordable technology for production of alternative protein and other functional food ingredients. The goal is to “close the loop” in the Swiss dairy sector by finally converting the algal biomass grown in dairy side streams into high-quality food products. The approved species of microalgae employed are well known for its nutritional quality, robust growth, and carbon fixation efficiency. Not only the vegan, protein- and PUFA-rich biomass will be produced but also they will be refined as food ingredients to be directly tested in at least two new products. Whey2blue will increase knowledge and acceptability of microalgae from stakeholders to end-consumers.