CO2 extraction is the best method to extract pure CBD isolate, after which it exists as a clear or white crystal. This method leaves practically zero trace of chemical contaminants in the end product. Alcohol extraction is another popular method. In this process ethanol, butane, or hexane is run through raw plant material to extract the CBD, before evaporating to leave only the active cannabinoid. Infusing vegetable oil is another effective way of extracting CBD.