Metabolomics is the data-driven science of small molecules. Untargeted metabolomics, using liquid chromatography-high resolution mass spectrometry (LC-HRMS), differs greatly from targeted metabolite assays, using nominal mass LC-MS instruments, as it generates thousands of metabolite features which are not quantified and are identified "post hoc." Thus, a substantial amount of time is dedicated to the data processing workflow. Despite the prevalence of untargeted metabolomics and LC-HRMS in contemporary research, undergraduate education in this area is almost nonexistent. To expose upper-division undergraduate analytical chemistry students to untargeted metabolomics, a realistic laboratory experiment, typical of biomedical research, was developed. In the clinic, hemolysis can result from poor sample handling. In this experiment, students artificially induced hemolysis in horse blood and assessed the resulting metabolomic differences. Using XCMS Online, an open-source online platform, and a guided worksheet, students navigated their processed data, learning how untargeted metabolomics differs from the targeted assays they previously performed. This experiment guided their understanding of key concepts such as the number of metabolite features detected, quality assessment, metabolite identification, and data visualization.