Terpenes and Temperature: What Difference Does It Make?
Terpene content is an increasingly powerful selling point for many cannabis brands, but these compounds are much more volatile than their phytocannabinoids counterparts like Tetrahydrocannabinol (THC) and Cannabidiol (CBD). With a bit of care and thorough cannabis testing, though, brands can prioritize terpene preservation and offer products that test higher for these valuable compounds.
In this blog, you will learn:
The boiling points of common terpenes found in cannabis
How to preserve terpenes with proper storage
How labs test for terpene profiles
A primer on terpenes
Terpenes cover a vast category of many volatile organic compounds found in thousands of plants around the world. Of approximately 20,000 known terpenes in all plants, around 200 have been identified in cannabis.
Terpenes play a big role of their own when it comes to the scents and tastes associated with cannabis, but as researchers learn more about the effects of terpenes on the body, a cultivar’s terpene profile is becoming just as important to consumers as a phytocannabinoid profile.
Why are terpenes so difficult to preserve?
Terpenes decay easily when exposed to environmental factors like oxygen, heat, humidity, and light. Once the cannabis plant is harvested, it is a race against the clock to preserve its terpene content. This also creates a challenge when it comes to cannabis testing labs attempting to analyze a sample's terpene profile. If the sample is not handled with care, terpenes can degrade so quickly the results will not be representative of the larger sample.
How temperature impacts terpenes
Terpenes evaporate off the plant in a way that phytocannabinoids like THC and CBD do not. That means if it gets too warm, either as part of the production process, lab analysis, or during consumption, those terpenes may simply disappear. Some terpenes will begin to evaporate off at temperatures as low as 70°F, although most will begin to degrade at around 100°F.
This has real effects not only for the taste and smell of the cannabis product, but also its effects. Terpenes, especially in combination with one another, can augment the effects of phytocannabinoids, a phenomenon called the entourage effect. For example, a common terpene profile that is thought to promote relaxing, calming experiences includes myrcene, beta caryophyllene, and linalool – these terpenes are often associated with a soothing effect. However, if these terpenes degrade or boil off before consumption, lab test results identifying and quantifying the terpenes won’t be useful any longer.
Common terpene boiling points
The boiling point of a terpene is the temperature at which it completely dissipates. This is much higher than the point at which terpenes begin to evaporate, yet still slightly lower than at which many phytocannabinoids burn off. Here are some boiling points of common terpenes found in cannabis:
Myrcene: Myrcene reaches its boiling point between 166ºC and 168ºC (roughly 330ºF). Myrcene is one of the most common terpenes found in cannabis. It is characterized by musky aromas and flavors. Myrcene can also be found in plants like eucalyptus, thyme, and hops.
Linalool: Linalool begins to boil off at 198°C (or 388.4°F). Linalool is also known for its relaxing effects, although it is usually less abundant than terpenes like myrcene. It is well known for its floral scent and is commonly found in lavender.
Pinene: Alpha pinene reaches its boiling point at 156°C (or about 312°F). Pinene is also found in pine trees and is thought to offer an uplifting experience.
Beta-Caryophyllene: Beta caryophyllene reaches its boiling point at a lower level than many other terpenes, starting to evaporate at 119°C (about 246°F). It is a unique terpene in that it influences the endocannabinoid system (ECS) much like a phytocannabinoid might. Beta caryophyllene is also found in black pepper, producing a smokey, peppery aroma and spiced flavor.
Limonene: Limonene boils off at about 177°C (just over 350°F). As the name suggests, limonene is found widely in citrus. Its flavors and aromas are much like that of a lemon, and the terpene is thought to add an energetic boost to the consumption experience.
These boiling points become important for consumers who are attempting to enjoy terpene content. For example, if your consumer wants to experience limonene terpenes, they may not want to heat their cannabis above 350°F without destroying the terpene content altogether.
As consumers become savvier cannabis shoppers, brands know they are curious about what terpene profiles work best for them. Lab testing can help pull back the curtain on which terpenes are present in which amounts and what proportions.
How are terpenes preserved?
Since terpenes are so delicate, great care must be taken to preserve them from the point of harvest onward. In cannabis flower, exposure to excessive oxygen, heat, humidity, and light could rapidly degrade the terpenes and reduce the overall quality of the cannabis. This means storage, shipping, testing, and distribution all pose a threat to terpene quality unless flower is stored in the following conditions:
Flower should always be kept at temperatures below 70°F after harvest.
Humidity levels vary but should generally remain between 45% and 65% after harvest.
Containers should be air-tight and allow no oxygen to enter.
Containers should be dark or opaque and allow no ultraviolet (UV) light to enter.
Preserving terpenes in concentrated extracts
Matters are more complicated for concentrated extracts. These products are typically made with the use of solvents like butane or ethanol and some require heat and pressure to create. Unfortunately, terpenes are too fragile to make it through these extraction processes; however, there are some extraction methods that preserve terpenes.
For terpene rich extracts, extractors typically reintroduce terpenes to the concentrate after it has been produced. To do so, extractors may use low temperatures to isolate and extract terpenes from another cannabis plant (or even another plant that contains terpenes entirely). Once extracted, these isolated terpenes can be added back into the concentrate to create a more flavorful product and augment the expected effects of the cannabinoids.
Once these terpene-added extracts are created, though, the same rules for storage apply. The terpenes added back into the extract can still easily degrade, and so concentrates should also be kept in cool, dark, dry, air-tight containers.
How terpene profiling is conducted
To perform terpene profiling analysis, cannabis testing labs rely on techniques like gas chromatography (GC). This method helps analysts determine the levels of each target terpene present in the sample by bringing them into the gaseous state and analyzing their relative masses and concentrations.
Terpene profiling demonstrates product quality
In the legal cannabis industry, brands need to set themselves apart by demonstrating product quality and safety to consumers. This is especially true in new markets like New Jersey, where recent cannabis legalization means an upsurge in new companies entering the space.
While New Jersey does not require terpene profile testing, consumers are choosing products more and more based on this information. Moreover, as the Garden State's adult use cannabis program comes online, it's possible the requirements may change to include mandatory terpene profiling. No matter whether you produce cannabis for the medical market or intend to work within the adult use market, True Labs for Cannabis performs detailed testing that identifies and quantifies terpenes with precision. Contact True Labs to learn more about our terpene profiling services.