Terpene Sources & Reading COAs

Why analyze a COA
A Certificate of Analysis, or COA, provides results obtained through testing companies on the composition of cannabis oils. With different analytical instruments like HPLCs and Mass Spectrometers, scientists can find the exact composition of a cannabis vape. It is very useful for determining the flavor profile of a vape and for trying to mimic certain strain flavors. It is also helpful to determine if the heating and filling processes have evaporated any terpenes, which would alter the flavor from the intended recipe.

Reading a COA

The COA above is a sample of live resin with certain identifying information blacked out to protect privacy. On the left in the sample above in blue, an HPLC has determined the concentration of cannabinoids – being a live resin sample cannabinoids are usually in the 60%-70% range which is normal and desired. On the right, in purple, a break down of the terpene percentage in listed. Notice the presence of Limonene at 1.93% off mass – this is a indication that this strain will have a noticeable lemon favor. The presence of caryophyllene terpene at 2.38% will result in a peppery flavor. This means that the dominate flavor in this stain will be a lemon pepper flavor of “Chemlatto”.

By mimicking the terpene amounts, this is how many terpene companies make specialized blends, which is done with mixing monoterps.

Monoterpenes 

Monoterpenes are a class of aromatic volatile compounds found in cannabis and other plants, giving them their sensory profiles (flavor and scent). Examples of monoterpenes include: pinene (pine scent), myrcene (hops / earthy scent), and linalool (lavender / floral scent). Companies will add monoterpenes in different combinations and percentages to distillates to create unique or strong flavored distillates.

Botanical terpenes are usually by-products of industrial processes. For instance, D-limonene is the byproduct of citrus juice production. Citrus peels are collected from the process and then put into a press to squeeze out the oils in the rinds.

Some botanical terpenes can be synthesized from petroleum products or from resveratrol in grapes.

For distillate vapes recipes, it usually reads like the COA above and mimicking the terpene percentages. However, it will lack the “body” and aftertaste found in live resin created by different phenols and ester compounds from the plant.

Steam Distilled Terpenes

Steam-distilled terpenes come from cannabis or hemp and can be bought from many terpene shops. These terpenes are separated from actual cannabis or hemp plants and contain a complex mix of flavors. Steam distilled terpenes, while common and easy to buy, is the most inferior of the distilled terpenes. Water during the distillation process, creates azeotropes with certain polar terpenes and are carried way and discarded.

Vacuum Distilled Terpenes

Vacuum distilled terpenes are derived from live resin and are removed by careful adjustment of vacuum under low heat. This is the superior terpene mix; however, this mixture is difficult to buy due to its stain-specific rarity. This mixture has many more delicate flavors than steam distilled mixes and is the closest representation of live resin.

Cannabis / Hemp Derived Terpenes

Functionally known as the “sauce” layer, these terpenes are a complex mixture of plant flavors and organic compounds from a cryogenic BHO extraction process. After BHO extraction, the THCA is allowed to crystallize for 1-2 weeks. This crystallization process expels the “sauce,” which is then separated by gravity or centrifugation.

The image above is “sauce” being poured off from a THCA crystallization process. Notice the THCA solids expelled from the sauce layer. This sauce layer can be mixed back with distillate to create a live resin vape or with diamonds to create a dab. The resulting mixture is an accurate representation of the flower, without burning the leaves.