The epistemic understanding of science has always been an important part of science education, and critical engagement with socioscientific issues (SSI) is a desirable outcome of scientific literacy. However, investigations into the link between these two concepts have been inconclusive. Many students have very limited interest in epistemic understanding as they engage with SSI. This intervention study aims to address this gap between knowledge and practice, to promote students' use of epistemic understanding, and to evaluate SSI through a practice-based approach, using the Apt-AIR framework (Barzilai and Chinn in J Learn Sci 27(3):353-389, 2018). The participants were 109 undergraduate students with various majors. A variety of measures were administered before and after a general education course titled "Making Sense of Science-related Social Issues", including an essay writing task to assess the participants' use of epistemic understanding when evaluating SSI, and a reflective task with follow-up interviews to identify the teaching components that could explain the students' changes in ability, if any. Statistical analyses of pre- and post-course performance revealed a significant shift toward epistemic understanding (p<0.00001). The qualitative data provided insight into the teaching components leading to this shift, and suggested interconnections between aspects of the Apt-AIR framework. The results of this study support a shift in practice for learning about science, and they highlight the need to link epistemic understanding and practice for a multi-perspective evaluation of SSI.