Organoleptic testing brings a human touch to each step of the CPTG quality control process. Organoleptics include those attributes of an essential oil that can be tested with taste, sight, touch, and smell. From growers and harvesters to essential oil chemists; from manufacturing engineers to essential oil practitioners; doTERRA’s global network of essential oil providers carefully monitors the quality of each CPTG Certified Pure Therapeutic Grade® essential oil. The extraction of essential oils is very much an art form that can be enhanced by, but not replaced with, mechanical analytics. The wisdom and experience of doTERRA’s essential oil experts are an indispensable part of the CPTG quality control standard.