Cannapedia Encyclopedia of cannabis strains


The aroma of cannabis, that is its specific scent and odor, is caused by substances called terpenes or terpenoids. About 140 different terpenoids are found in cannabis which results in typical smell of individual strains.

Isoprene units (C5H8) form monoterpenes (C10H16), sesquiterpenes (C15H24), diterpenes (C20H32) and triterpenes (C30H48). Terpenoids can be acyclic, monocyclic or polycyclic hydrocarbons with substitution models including alcohols, ethers, aldehydes, ketones and esters. That is why some strains of cannabis have a stronger smell than others.

How to extract cannabis aroma

The essential oils can be easily acquired by using steam distillation or vaporization. The amount extracted depends on the type of cannabis (high-potent, industrial hemp), pollination, the plant’s gender, its age, which part of the plant is used, whether the plant is grown indoor or outdoor, under which circumstances it is harvested, the degree of dryness, and the storage conditions.

For example, processing fresh cannabis buds of the Afghani strain should yield about 0.29% of the essential oils. As a consequence of drying and storing, the content drops to about 0.20% after one week, and after three months it is at 0.13%. According to the experts, the loss is considerably bigger in monoterpenes than in sesquiterpenes; however, none of the major compounds fully evaporates during this period.

Basic facts about the aroma of cannabis

  • Cannabis contains over 120 different terpenes. Some of them only in trace amounts, others in two-digit percentiles in some strains.
  • Terpenes are formed in trichomes, the resin glands in which also THC and other cannabinoids are formed. Terpenes account for 10-20% of all oils formed by trichomes.
  • The narcotic detection dogs detect the scent of aromatic terpenes, not THC.
  • The plant’s age, ripeness, and the part of the day can influence the amount and proportion of the terpenes. Their formation is a continuous process, but they evaporate due to heat and sunlight.