The author argues that organic-coffee certification enacted under the rubric of transnational certification norms alters the logic and practice of economic management and governance in an Oaxacan (Mexican) peasant producers' union. As the title indicates, these changes are productive of social and economic tensions. An economic and ethnographic analysis of ‘certification labor’ demonstrates (a) that the work of certification is distributed within producer organizations such that village and regional leaders become burdened by significant new responsibilities, and (b) that practical changes—including a new producer logic (‘market-price interdependence’) and village certification-service providers (‘peasant inspectors’ and ‘community technical officers’)—have a significant qualitative impact upon household and village economic governance. In addition, certification (c) affects the operation of statewide producer unions, altering the ways in which these interact both with their member organizations and with certifiers: unions must intervene to aid (regional) member organizations in their efforts to certify, yet also find that certification norms, such as conflict-of-interest provisions, constrain the union's ability to promote producer interests. Thus a qualification to an organic and ethical-products literature that conflates quality certification with the protection of smallholder cultural and economic independence is provided. The author concludes that a rethinking of certification norms, together with efforts to assist producer certification, should be a priority for supporters of sustainable agriculture.