Chirality transfer across length scales is an intriguing and universal phenomenon. Both in nature and in materials science, complex architectures composed of bio-based chiral building blocks are responsible for unique optical responses from bright and vivid colourations to extremely large dichroism. When it comes to working with naturally derived chiral building blocks, however, the challenge lies in understanding how the properties of individual building blocks relate to the emergent features of large-scale architectures and structures. Our research addresses this gap by investigating the origins of mesophase chirality in bio-derived particles such as cellulose and chitin nanocrystal suspensions. Through a combination of quantitative morphological analysis of individual nanoparticles, final architecture, and their assemblies, we showcase the functionality of such chiral materials in the context of optical materials, including plasmonic ones, also providing examples of how such materials can be produced at scale.