This article analyses the role of intermediaries’ engagements to bridge the gaps between research, education and practice in the processes of knowledge production needed for the shift to sustainable agri-food systems. It is based on an immersive study of an intermediary organization in the USA, including comprehensive interviews with the staff of the organization about their professional activities, their career paths, their close and longstanding professional relationships, and their values. Three characteristics of engaged intermediaries are identified, which can be positive add-ons for bridging activities: they consider farmers and scientists as equal contributors to the production of knowledge; they are involved in multiple life-worlds: for instance, being both a farmer and an outreach specialist or scientist; and they are closely associated with movements furthering the development of local and sustainable agri-food systems and an equitable sharing of knowledge. The article addresses topics often neglected in the innovation systems literature: the experience, social relations and political engagement of intermediary actors.