These collective expert scientific studies on “herbicide-tolerant varieties” involved some twenty experts from very different disciplines in a “sensitive” topic. This article describes how the experts were chosen, how they interacted with their ministerial clients, how the group of experts functioned and the outcomes of its assessments. It investigates the way minority opinions were handled by the expert group, as well as the crucial question of recognition of the work of the scientists who took part, in relation to expectations among the research organisations.