Although sargassum is not edible, turning its ash into a glaze makes food contact possible. Firing releases the metals present in the seaweed and creates a raw material for ceramics. We carried out the entire research and development phase to obtain different recipes for a viable glaze. The result is three finishes: gloss, matt and satin. Applications range from tableware to cladding tiles for architecture or furniture. These objects could make it possible to put sargassum to use on a large scale.