Affective and cognitive processes may be jointly researched to better understand mathematics learning, paying special interest to emotions related to knowledge acquisition. However, it remains necessary to explore these processes in studies linked to the education of pre-service mathematics teachers. This study aims to characterize epistemic emotions in different practices linked to the practice of mathematics teaching: problem-solving, anticipating what would happen with the students and reflecting on classroom implementation. It considers the theory of Mathematical Working Spaces to describe the mathematical and cognitive dimensions generated by epistemic emotions, paying special attention to the cognition-affect interaction and the workspace created. The results indicate that the epistemic emotions of the pre-service mathematics teachers associated with the distinct practices were different. Differences are observed in the interaction between emotions and cognitive epistemic actions, depending on whether the pre-service mathematics teachers analyze them within the framework of their own solving or anticipate them in their students. This reveals how personal work relates to what is considered to be suitable for students. Specifically, certain antecedents and consequences have been specified for the emotions of surprise and boredom in relation to the characteristics of the optimization problems and the cognitive activity of the subject when solving them. These results highlight the need to enhance the education of pre-service mathematics teachers through training that helps regulate their epistemic emotions and model effective strategies for regulating their own emotions and those of their students.