This communication is grounded on previous elaboration of the notion of out-novation (Levain et al., 2015) or ex-novation (Wolff et al., 2007; Martin et al., 2016) after the seminal inputs of reflection about de-institutionalization process (Maguire et Hardy, 2009) and the idea of detachment in innovation process (Goulet & Vinck, 2012). The aim is to tackle the pending issues of sustainability transition where intermediaries have a key role in “pushing and tracking” transformative policy towards the abandonment of established but weak practices within a stable sociotechnical regime. Many sustainability transition paradox and challenges are at stake in the present agri-food system, calling for more research on intermediation and learning processes in a call for generalization of sustainable practices (Elzen et al., 2012 ; Hermans et al. 2013 ; Klerkx ert al. 2010). The role and function of intermediaries in concomitant deinstitutionalisation process of certain practices and out-scaling process of novel practices has not been that much put under empirical investigation and intermediation in transition suffers from a lack of theorizing (Steyeart et al., 2016). This communication intends to frame an answer based on the case study of intermediation of pesticide use in France during the last decade (Cerf et al., 2017). It reports about a longitudinal study with participatory momentum inclined to elicit the views, practices and conditions of action of those sustainability transition intermediaries. Some key findings point the need to open the understanding of the chasm of out-novation. In many circumstances the dynamic of sociotechnical regime and de facto governance of transformative process, do not mean only de novo creation, nor substitution, but more often a subtle agency and structure of de-framing, re-agencing and including critical mind-sets, new sociotechnical agency and human practices (Turnheim et al., 2015). The chasm of innovation (Bernstein &Singh, 2008) has its counter part in what one could name the chasm of out-novation or ex novation. As a generalisation process relays on the often silent but determinant contributions and actions of innovation brokers, sustainability transitions supposes intermediaries that convey the uptake of a critical zone of out-scaling. This perspective has to be clearly put upper in the agenda of Transition Studies.