Updated project metadata. Natural materials can reversibly self-assemble into hierarchical networks with diverse structural and functional properties. Recreating these dynamic architectures using peptide-based synthetic materials has been an elusive goal, hindered by challenges in relating sequence to structure to function. Here we report on the de novo discovery of short peptides based on the “tryptophan zipper” (Trpzip) motif that self-assemble into hierarchically structured hydrogels. Trpzip hydrogels have a tunable modulus and show self-healing, stress relaxation, antimicrobial properties, and biocompatibility. The low yield point allows syringe extrusion with cytoprotection, and cell harvest with a flick of the wrist. Integrating a pendant cell adhesion motif promotes human intestinal organoid growth and differentiation, with polarity control and improved shape fidelity. Considering these unique characteristics, we anticipate Trpzip hydrogels will prove a versatile reagent for biotechnology and medicine.