This article deals with practices of collective composting, analysed on the basis of a field study carried out in the Lyon metropolitan area. These practices, initiated by inhabitants and associations, tend to be recognized and institutionalized. They consist in diverting fermentable materials from waste flows, and rely on a sophisticated regulation, while carrying pragmatic, political and moral values. The analysis aims to highlight the organization through which actors circulate organic waste in a way that favours proximity and citizen involvement, and in so doing, diverts it from mainstream waste management. We show how the circulation of these materials consists in ‘shorting’ the established sociotechnical system of waste management, while adjusting to it. As a result, the material dimension of this waste appears as engaging multiple and intertwined circuits defined as financial, ethical, ecological, social and political.