Organic policies have become an important strategy to increase the sustainability of food systems. Procurement of organic foods for the public is an important part of such strategies. Policymakers have become aware of the way through which food economy can be influenced more sustainably through the implementation of greener procurement practices. The value of food bought by the public for settings such as schools, hospitals, canteens, and care homes is considerable and provides a strong rationale for public organic policies. However, such policies require well-planned implementation and involve a multitude of practitioners. Changing practices require the backstage support of both policymakers and food professionals as well as support from the frontstage actors – the users of the canteens. The paper examines whether organic food-based diets could be implemented in a semi-captive environment, such as that of army foodservice, for the mutual benefits of both consumers and policymakers. We studied the Canteen2018 intervention implemented over 8 months period with a targeted increase of organic foods shares to the “silver” or “gold” level of the Danish organic label. Results show that such a change process creates tensions in the interface between the user, the staffs, and the policy levels, but that it was possible to increase the amount of organic share without radically compromising the overall user satisfaction. Organic conversion in the semi-captive food environments as those of army canteens is possible if due consideration is given to planning, monitoring, education and learning, information and communication, stakeholder involvement, and experience sharing.