No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has an added environmental benefit: It uses local ingredients and recycled products. This lab also encourages student inquiry into a multitude of interdisciplinary topics--and your students will enjoy sampling the results of their scientific endeavors. (Contains 1 figure.)