Secondary students are increasingly involved in scientific research projects that include authentic disciplinary literacy components such as research proposals, posters, videos, and scientific research papers. More and more, students are also engaging in professional practice of publishing their scientific research papers through dedicated secondary science journals. Peer-review and publication are important parts of the scientific enterprise, and research has shown that engaging students in such scholarly practices helps build their sense of belonging and scientific identity. Yet, these disciplinary literacy skills and professional practices are often part of the hidden curriculum of science research, thus excluding students and others from fully understanding ways in which scientific knowledge is constructed, refined, and disseminated even though students are participating in such activities. As more students participate in research experiences and the dissemination of their work, it is important to understand how teachers and other mentors support the development of disciplinary literacies, including those that are deemed professional. To this end, we used a mixed-methods study of interviews and surveys to examine the experience and conceptions of the mentors (teachers and professional scientists) who guided pre-college students through the writing and publication of their scientific research projects. Our findings reveal that mentors have divergent views on the value of publication within science versus for student scientists. Additionally, analyzing our data from a lens of cognitive apprenticeship we find that mentors encourage independence by primarily employing the method of exploration. Our findings suggest that mentors could work to explicitly reveal their own thinking within science writing and provide more sequenced support for student scientists.