Course-based authentic research is an effective and appropriate substitute for mentored research with undergraduates to both engage students in the process of science and to foster the skills and knowledge development required to successfully pursue advanced studies. Here we describe a very flexible olfactometry system that can be used for a wide range of open-ended experimental studies using the bean beetle, Callosobruchus maculatus, model organism. The essence of this olfactometer is a Y-maze in which individual beetles choose between two sources of chemical signals. We will use this system to address questions about mate choice by males in this species. This system may be used with a guided-inquiry pedagogy to start a process that leads to students posing their own questions and pursuing authentic research projects.