Essential oils are valuable products commonly employed in the food industry and extensively studied as biopreservatives for the extension of food shelf life. Unfortunately, essential oil might be counterfeit to increase industrial profile. The formulation of medicinal products with counterfeit and adulterated essential oil could be very dangerous and put in serious risk to the health ofconsumers. Only by ensuring the quality of essential oils by means of the most appropriate analytical strategies, the best benefits of these products would be possible. Adulteration is difficult to identify by visual and sensory inputs alone. Today’s advanced technology for essential oil adulteration detection encompasses many analytical techniques but only few of them absolutely guarantee its composition and purity. So in the present study, we aimed to characterise spice essential oils and also study the effect of adulteration in essential oil using optical properties. The simplest, fastest and non destructive way to measure the quality standards of essential oil is to measure the physical parameters like specific rotation and optical rotation by using polarimeter. At first, measurements were made of the optical rotation of 14 distinct essential oils at various temperatures and concentrations. The potential adulterants were blended, and the trials for adulteration detection using optical characteristics were repeated. The existence of adulterants can be determined based on differences in the specific rotations that are analysed from the graph in relation to different specific rotations that relate to potential adulterants in the sample. The present study was successful in developing optical property-based method for detecting mixing of cinnamon leaf oil in cinnamon bark oil as well as turmeric leaf oil in turmeric rhizome oil.