Food waste has serious economic and environmental repercussions, and there is growing policy attention to this issue in Canada. This study investigates how the material characteristics of wasted food influence its circulation and management in the City of Guelph, Ontario. Based on interviews with informants across the food value chain, we learned that there is a high reliance on systems and techniques to determine when food becomes waste (including cold chains, best before dates, and aesthetic standards). We document how these systems pervade the food chain and food recovery efforts, and also note attempts to disrupt their momentum. Our analysis emphasizes the relational agency of food waste: how social and cultural contexts interact with food's vital materiality in the determination of when it becomes waste, the circumstances under which waste can become food again, and how organic matter can find a second life as a source of energy and nutrients. ARTICLE HISTORY