<p>Making agri-food systems in Europe more sustainable often requires systemic change. Transformative rather than incremental change is difficult if agri-food systems are locked into unsustainable practices by a range of institutional, cultural, social and financial factors that create mutually reinforcing barriers to change. Institutionalised public policies tend to further stabilise the established system through multiple feedback effects, bolstering unsustainable path dependencies. Co-design has been discussed as an innovative approach to developing operational options in agri-food systems. However, co-design methods have rarely been applied to develop policy options. This paper presents the experiences with a policy co-design process for the envisioned sustainability transformation of conventional pork production in Brandenburg, Germany. Combining an agri-food system perspective with the policy co-design literature, we developed (1) a process template for a participatory policy co-design process to overcome barriers and lock-ins along the three levels of policy mixes: objectives, instruments and calibration; and (2) a conceptual framework for the systematic analysis of this process and its output. The successful implementation of the policy co-creation process in the case study constitutes a proof of concept. An unexpected limitation was that full specification of instrument calibrations was not realistic. In policy processes, this is typically part of hard negotiation processes. The systematic analysis of the participatory development of policy options along the three levels of policy mixes confirms and refines the possible role of co-design approaches for public policies in the transformation of agri-food systems.</p>