Terpenes are a form of aromatic organic hydrocarbon. There are around 140 different kinds of this chemical compound found in the cannabis plant, and you may have heard people talk about them, or reference terpenoids in relation to cannabis. While many people use the terms terpenes and terpenoids interchangeably, they are actually slightly different things. Terpenes are a type of hydrocarbon (they are made entirely of carbon and hydrogen), while terpenoids may have been chemically modified, and at the very least have been denatured through a process called oxidation.
Terpenes are made by cannabis plants using secretory cells, and they are typically found in the highest concentration in an unfertilized female cannabis flower, before the flower starts to deteriorate through age. Terpenoids are extracted from the plant using either vaporization or steam distillation. A lot of the most useful terpenes vaporize at 157 degrees Celsius, which is the same temperature that THC boils at, but there are some which are a bit more volatile. The terpenes, in the plant, act as a protective substance preventing the growth of bacteria and fungi, and also protecting the plant from insects.
THC is the cannabinoid that is most well-known and that has been most carefully studied, because it is the psychoactive part of the plant. The role of the other cannabinoids, flavonoids and terpenoids that are a part of cannabis is something that is not fully understood, but it is generally accepted that they all have a role to play in terms of a therapeutic effect.
Terpenes contribute to the aroma of cannabis, and it is thought that the different aromas can actually give an indication of the different effects, although it could be a psychological impact rather than something that is truly a scientific difference. It is generally agreed that musk or clove smelling terpenes are present in the plants that have the more sedating, relaxing effects, while pine-like aromas are associated with alertness and memory retention, and lemony-aromas help to improve mood.
Terpene isolation is an area that is getting more and more attention, and many people are looking into the idea of doing it at home. Some people use vacuum drying ovens to extract the oil, but there are flaws with this process. To properly extract the terpenes, it is important to make sure that excess moisture and solvent is trapped and does not contaminate the extract.
With older drying methods, it is not uncommon for cannabis extract to have little or no flavour. The problem is that the concentrate is being over purged, and people end up collecting large volumes of water, some alcohol, but only a minute amount of the valuable (but volatile) terpenes. It takes winterizing the solution to get the actual terpenes.
The system of using a cold trap and tepene collector is something that could be game-changing, allowing the average fan of hash to collect their own, pure terpenes and even make flavourful cannabis concentrates. The more we explore the idea of terpenoid isolation, the more we can learn about the properties of the plants, and who knows what synergies we might find between the terpenoids and the rest of the plant. Cannabis studies are only just beginning to pick up pace and we are learning things about them every day. It’s likely that the interactions between different cannabinoids, flavonoids and terpenoids is what contributes to the power of the plant and that collectively their interactions are more powerful on the human body than their individual compounds suggest, but until we can explore them in isolation we have a lot to learn.