This article traces the creative reconstitution of the Canada-UK wheat-bread commodity chain since the 1990s. In the mid-1990s, the Canadian Wheat Board (CWB) and a British bakery, Warburtons, pioneered an innovative identity-preserved sourcing relationship that ties contracted prairie wheat growers to consumers of premium bread in the United Kingdom. The CWB-Warburtons contract is emblematic of the increasing importance of quality claims, traceability, and private standards in the reorganization of agrifood supply chains. Yet the case is unique in two important ways. First, in the context of supermarket leadership in the coordination of quality chains, the program was established by two unlikely actors--a state marketing agency and a branded food manufacturer. Second, the quality chain centers on a semifresh, manufactured food staple (bread), whereas most quality chains are organized around fresh produce, meat, and dairy products. The CWB-Warburtons story thus provides evidence of diversity and complexity in the shift toward the supermarket-driven "economy of qualities." I interpret these changes by locating them in broader processes of historical change. Led by the CWB and Warburtons, the shift toward quality in commodity chains for wheat bread is reconfiguring relations among key social actors in the prairie wheat economy as well as the UK bread market.