This paper contributes to the emerging debates on the importance of materials to economies by examining the role of sulphur dioxide (SO2) as a vital material in the organic wine markets. The paper draws on the performativity programme developed by Callon and others (see e.g. Callon, 1998), and the consequent examination of the role of material devices in the performative and dynamic nature of markets. Such research has so far primarily focused on financial markets (e.g. Muniesa 2008), although some recent research has also focused on materialities in other markets (e.g. Gregson 2010). The paper widens the scope of this approach by marrying performativity with materiality from the chemical level up. 

I discuss the active role of SO2 as a material which plays a crucial part in the marketization (Çalikan and Callon 2010) of particular wines. As a preservative, SO2 'pacifies' organic wines and enables their entry into international wine markets, in which goods need to 'hold on' to their qualities for thousand-mile journeys across different environmental conditions. Low-sulphur wines do not exhibit the same robustness, and their participation in these markets is limited. Instead, 'artisan' wines depend on strong inter-personal networks of trust and knowledge for their marketization. This organising effect of SO2 has a further normative dimension. The spatial and emotional alienation of organic wines from the place of production in the international markets fits awkwardly with the locally-sourced, slow-food discourse which is a key moralising 'story' of organic products. A clash between different enactments (Mol 2002) of SO2 emerges: as an enabler of marketization, and as a marker of commitment to organic principles. SO2 is thus a crucial part of these socio-technical agencements (Callon 1998), and the unpacking of SO2's significance yields important insights into both the construction of, and the moral discourses surrounding, organic wine markets.