Essential oils serve as a valuable, inexpensive natural supply of useful organic compounds that possess various biological activities, including antimicrobial properties, and most oils emit pleasant and familiar odors. They are an excellent source of analytes for introductory organic laboratory experiments. We report an experiment in which students rapidly isolate the major components of commercial essential oils (clove, oregano, red thyme, spearmint) by a small-scale modification of dry column vacuum chromatography (DCVC), a convenient reduced-pressure alternative to flash column chromatography, using an apparatus easily constructed from common laboratory glassware. They then experimentally establish the antibacterial activities of the oils and their two major components by testing for inhibition of bacterial growth on a nutrient agar plate.