In a recent study published in the Journal of Industrial Crops and Products looking at cannabinoid and terpenoid profiles produced by popular extraction methods found using a combination of polar and non-polar solvents had a superior profile over other mixtures. When using an ethanol/hexane solvent mixture researchers were able to extract the highest levels of both cannabinoids and terpenoids compared to using one solvent.
Additionally, when using either a vacuum oven, rotary evaporator or genital nitrogen evaporation, the study found that nitrogen evaporation is far superior to both a vacuum oven and rotary evaporator. Both vacuum ovens and rotary evaporators were found to destroy a significant amount of terpenoids and seem counterproductive in producing medical-grade cannabis extract. Lastly, the position of the harvested plant material had a significant impact on the number of cannabinoids and terpenes produced in cannabis oil. Scientists found more cannabinoids and terpenes in oil that was generated from plant material harvested closest to the light source.
The findings of this study are significant to the home cultivator because one does not need expansive equipment to make high-quality cannabis oil. To receive the same results, one would merely create a cannabis tincture and let the alcohol slowly evaporate.
Namdar, D., Mazuz, M., Ion, A., & Koltai, H. (2018). Variation in the compositions of cannabinoid and terpenoids in Cannabis sativa derived from inflorescence position along the stem and extraction methods. Industrial Crops and Products, 113, 376–382. https://doi.org/10.1016/j.indcrop.2018.01.060