A science teacher educator returned to teaching adolescents after more than 10 years in the professoriate. We studied his beliefs, practice and daily use of inquiry pedagogy while implementing a reform-based curriculum. Reflection on practice was evidenced by a weekly journal, classroom observations and debriefings, and extensive interviews. Newly developed practical knowledge from this experience shifted the science teacher educator’s beliefs away from the Piagetian structuralism espoused in prescribed curricula towards a more culturally responsive, student-driven approach to teaching science to middle grades students. The merits and limitations of curricula attempting to follow traditional scientific practices are discussed.