The purpose of this paper is to explore the issues that may affect the integration (i.e., the relationships) between the different actors that comprise a supply chain. Whist the theoretical part of the paper can be referred to any supply chain, the empirical part is focused on the UK barley to beer supply chain. The main motivation behind the topic is that improvements in the relationships amongst the different segments of a chain can enhance its efficiency and effectiveness, (e.g., through improvements in coordination and cooperation), and therefore, its competitiveness and long term sustainability. The paper is based on two complementary analyses: the first one consisted of a structural equation model (SEM) to determine those factors that affect the sustainability of relationships in the chain. The model is estimated based on a survey of 69 chain stakeholders. The second analysis comprised an in-depth case study based on an important malting-barley- to-beer supply chain in Eastern England, and had the purpose of providing further understanding of those aspects that were highlighted by the SEM. The overall results pointed out to five factors affecting the relationships in the malting barley to beer agri-food supply chain: communication, compatibility of aims in the supply chain, contractual relationships backed by professional regard and personal bonds; high levels of trust exist between the chain participants and a willingness to resolve any problems; and commercial benefit.