After the 2008 food price crisis, food security once again became a priority on the international political agenda. This introduction to the special issue tackles the links between this reprioritisation of food security on the one hand, and science and technology on the other hand. First, this special issue introduces the new controversies emerging around food security. Trying to articulate food security with other global issues, actors involved into these debates have elaborated at least two new food security frames, global food security and food sustainability. Second, this issue highlights the role played by knowledge infrastructures in shaping debates on food security. The formal constraints of models or foresights tend to format our ability to assess and act upon food insecurity. A sociological analysis of knowledge infrastructures thus helps to democratise food policies. Third, technosciences are embedded in dense fields of meaning, moral values and contribute to the making of sociotechnical imaginaries. The articles in this issue show that food security research is not just about knowledge, but also about how life ought to be lived. Last, food security articulates science with politics and policies. In particular, the debates about technologies are complemented by disputes about the regulations that should encourage or oppositely restrict their implementation.