Non-major students taking science courses to fulfill degree requirements may show low interest in traditional lecture-based classrooms. While professors may try to incorporate hands-on activities to the classroom to foster enthusiasm, the development of a low-cost, low-hazard scienitfic activity that engages students can be challenging. Moreover, teaching and evaluating critical thinking, scientific literacy, quantitatve analysis and writing skills utilizing such activities require asking carefully designed questions. Here, I introduce a tested effective, inexpensive, 20-minute in-classroom microbiology deep-learning activity, and explain how it can be adapted to other disciplines of science. From one simple exercise, students conducted literature research, performed statistical analysis and made quantitative/causative conclusions. Students also learned to write, appreciate and critically analyze a scientific paper.