This article draws on findings from a multi-sited study of international science policy processes in rice biofortification. It focuses on the ten-year period between the discovery of a “high-iron” elite line named IR68144-3B-2-2-3 and the publication, in 2005, of the findings of a bioefficacy study that proved crucial to securing the support necessary to scale up biofortification research as a global Challenge Program. During this time, IR68144 took on many guises, defined and redefined in relation to different disciplinary, institutional, and sociocultural perspectives. This article highlights the ways in which different actors responded to the material agency of IR68144, drawing implications for reflexive practice and context responsiveness in a research effort increasingly distant from its projected beneficiaries. The case of iron rice research shows that while attempts to shape rice (in whatever form) to suit a particular research or policy agenda may be successful within carefully tailored and time-bound settings, once these conditions are removed, the reality of rice, in all its complexity and heterogeneity, inevitably bites back. Today, the center of gravity of rice biofortification research is located in a more mobile global science community. This article shows how an instinctive appreciation of the materiality of rice, in interaction with humans (researchers and their subjects) and other material elements, was a key factor that differentiated the early research practice from that of a new generation of scientists attempting to achieve a set of global research targets.