In the wine‐producing region of McLaren Vale, South Australia, the development of a detailed geology map has worked to increase understandings about the physical diversity of vineyard land. I argue that the production and deployment of social/scientific knowledge through the map is instrumental in strategic imaginings of the viticultural space of McLaren Vale. Ethnographic examination of ‘District Tastings’ of single‐vineyard Shiraz wines shows how the geology map provides a framework for understanding and promoting relationships between vineyard geology and wine flavours. This process feeds into debates over possible delineation of official winemaking ‘subregions’, which may provide a mechanism for the generation of economic value based on discourses of quality and distinctiveness. The map's depiction of geological diversity is embraced by wine producers, who seek to add value to their product through appeals to a purported uniqueness, scarcity or specialness based on geological terroir.