Terpenes & Temperature: A Crucial Factor in Cannabis Testing
Introduction: Terpenes, the aromatic compounds found in cannabis, are gaining prominence as a key selling point for many cannabis brands. Unlike their more stable counterparts, such as Tetrahydrocannabinol (THC) and Cannabidiol (CBD), terpenes are highly volatile. However, with meticulous care and comprehensive cannabis testing, brands can prioritize terpene preservation, ensuring their products contain higher levels of these valuable compounds.
In this article, we will delve into:
- The boiling points of common terpenes in cannabis.
- Strategies for preserving terpenes through proper storage.
- The methods employed by labs to test for terpene profiles.
Understanding Terpenes: Terpenes constitute a diverse group of volatile organic compounds found in thousands of plant species worldwide. While around 20,000 terpenes are known to exist across all plants, approximately 200 have been identified in cannabis. Terpenes not only contribute to the scents and flavors of cannabis but are also gaining recognition for their potential effects on the body. As researchers uncover more about terpenes, a cultivar’s terpene profile is becoming just as significant to consumers as its phytocannabinoid profile.
The Challenge of Preserving Terpenes: Terpenes are highly susceptible to degradation when exposed to environmental factors such as oxygen, heat, humidity, and light. Once cannabis plants are harvested, a race against time begins to preserve their terpene content. This challenge extends to cannabis testing labs attempting to analyze terpene profiles. Without careful handling, terpenes can degrade rapidly, rendering the results unrepresentative of the larger sample.
The Impact of Temperature on Terpenes: Terpenes evaporate from the plant in a manner distinct from phytocannabinoids like THC and CBD. When exposed to excessive heat, whether during production, lab analysis, or consumption, terpenes can quickly dissipate. Some terpenes may start evaporating as early as 70°F, with most degrading around 100°F. This has real consequences not only for the taste and aroma of the cannabis product but also for its effects. Terpenes, especially when combined, can enhance the effects of phytocannabinoids, a phenomenon known as the entourage effect.
Boiling Points of Common Terpenes: Understanding the boiling points of terpenes is crucial for consumers looking to enjoy their terpene content without losing them. Here are the boiling points of some common terpenes found in cannabis:
- Myrcene: Boiling point between 166ºC and 168ºC (approximately 330ºF). Known for its musky aromas and flavors and also found in plants like eucalyptus, thyme, and hops.
- Linalool: Begins to boil off at 198°C (or 388.4°F). Recognized for its relaxing effects and floral scent, though usually less abundant than terpenes like myrcene. Commonly found in lavender.
- Pinene: Alpha pinene reaches its boiling point at 156°C (about 312°F) and offers an uplifting experience. Also found in pine trees.
- Beta-Caryophyllene: Starts to evaporate at 119°C (about 246°F) and influences the endocannabinoid system. Found in black pepper, producing a smoky, peppery aroma and spiced flavor.
- Limonene: Boils off at about 177°C (just over 350°F), imparting an energetic boost. Abundant in citrus plants, with flavors and aromas akin to lemon.
Preserving Terpenes: Given the fragility of terpenes, meticulous care is essential to preserve them from harvest onwards. For cannabis flower, storage conditions should minimize exposure to oxygen, heat, humidity, and light. Ideal storage conditions include:
- Keeping the flower at temperatures below 70°F after harvest.
- Maintaining humidity levels between 45% and 65% post-harvest.
- Using airtight containers that prevent oxygen exposure.
- Employing dark or opaque containers that shield against ultraviolet (UV) light.
Preserving Terpenes in Concentrated Extracts: Preserving terpenes in concentrated extracts is more complex. These products often involve the use of solvents and heat, which can be detrimental to terpenes. However, some extraction methods can preserve terpenes. For terpene-rich extracts, extractors usually reintroduce terpenes to the concentrate after production. To achieve this, extractors may employ low temperatures to isolate and extract terpenes from another cannabis plant or another terpene-containing plant entirely. Once isolated, these terpenes can be added back into the concentrate, enhancing flavor and the expected effects of cannabinoids. The same storage rules apply to these terpene-added extracts to prevent degradation.
Terpene Profiling Analysis: Cannabis testing labs conduct terpene profiling analysis using techniques like gas chromatography (GC). This method helps analysts determine the levels of each target terpene present in the sample by converting them into a gaseous state and analyzing their relative masses and concentrations.
The Significance of Terpene Profiling: In the legal cannabis industry, demonstrating product quality and safety is crucial for brands, especially in emerging markets like Minnesota. While Minnesota currently does not mandate terpene profile testing, consumers are increasingly selecting products based on this information. As the state’s adult-use cannabis program takes shape, regulatory requirements may evolve to include mandatory terpene profiling.