Can we eat Earth Buildings? The mineralogical common of earth building and edible earth practices

Earth-based materials (namely, mud or dirt architecture) have been used for over millennia and are still sheltering approximately a third of the world population. These materials are currently experiencing a new Renaissance with construction methods and digital fabrication technologies that are highly focused on the mineralogical and particle characterization of optimal mixtures. Similarly, clay-based materials have been traditionally used as edible substances in almost every region globally: from the Middle East to India, and from Western Europe to the Caribbeans and Africa. Traditional recipes such as bonbon tè (Haitian mud cookies) and the Calabash Chalk (West Africa) have been used as part of human diet for religious beliefs, traditional local medicine, or as part of a regular supplement, a custom that has been interpreted by Western investigators as a pathology named Geophagia. This article presents a theoretical and experimental research-by-design investigation into the mineralogical content within earth materials and its role in building and human metabolism. A critical literature review on earth materials and their particle mineral content is presented, while analysing, comparing, and contrasting the ingredients that make a good buildable and edible earth artifact. The analysis reveals that both buildable and edible soil compositions share a common mineralogical base: the microstructure and water absorption capacity of clay minerals. The research-by-design process included creating buildable and edible artifacts based on traditional and current practices following the literature review. The project culminated in an architectural installation that maps earth artifacts for their compositions, critically contributing to the architectural field by provoking questions regarding the mutual dependencies between humans and their surrounding natural resources, while testing ideas and beliefs regarding the nature-culture divide that governs existing environmental paradigms.