Liquid-liquid phase separation (LLPS) is a process in which biomolecules coexist in two distinct phases. For example, proteins can separate from solution as liquid droplets. Such droplets often harden... A minimal protein-derived biomolecule forms liquid droplets that mature into hydrogels and liquid-liquid phase separation droplets. Adding zinc increases stability and improves the catalytic and adhesive performance of the material. Such droplets often harden into fibres over time.