In a previous analysis, we saw which extracts contain the most terpenes, in general. However, the type of extraction method that contains the most terpenes might not be preserving them in the same way they occur in the plant. Confused? Read on.
In the article Which Extract Has The Highest Terpenes, we pooled terpene profiles together and calculated which ones had the highest levels of cannabis terpenes. Budder and shatter (both BHO) tied for First Place, dry-sift non-solvent hash came in Second Place, live resin took Third Place, crumble followed with Fourth Place and rosin took Fifth Place. This ranking looks at sheer levels of terpenes, and does not qualitatively analyze what kinds of terpenes they had.
Here, we look at the ratio of the two general classes of terpenes present in cannabis: monoterpenes and sesquiterpenes. Monoterpenes (mainly myrcene, alpha-pinene, beta-pinene, limonene, linalool and terpinolene) are always present in higher amounts than sesquiterpenes (mainly caryophyllene, caryophyllene oxide and humulene), largely due to the fact that myrcene, a monoterpene, is present in such large quantities in all cannabis.
As seen in an analysis done at the University of Mississippi, the level of monoterpenes goes down quicker than that of sesquiterpenes during the curing process largely due to the fact that monoterpenes evaporate more readily. By looking at the ratio of monoterpenes to sesquiterpenes one can use a terpene profile of an extract to see how close it comes to that of dry or fresh buds.
How can we use this ratio? This number can be used as a rudimentary way of knowing how true an extraction method preserves terpenes from the raw (but cured) cannabis flower. The average of the monoterpene-to-sesquiterpene ratio of a pool of indica-dominant strains was 16, the average for a pool of sativa-dominant strains was 13, and the average of a pool of hybrid strains was 6.17. Taken together this average is 11.6.
As you can see from these ratios, monoterpenes occur at higher levels than sesquiterpenes. Any disturbance in this ratio doesn’t make an extract smell bad, it just smells different, unique, and in some cases, utterly breathtaking.
None of these extraction methods make it past 7 for the ratio. Therefore, the higher the ratio of monoterpenes to sesquiterpenes for an extract means it comes closer to the terpene content of herbal cannabis. This doesn’t mean anything for the actual fragrance of the extract; it just means it did a better job of pulling out terpenes at relatively the same level as they occur in the plant.
We gave First Place to shatter BHO with a ratio of 6.65.
Budder BHO took Second Place with 6.58 monoterpenes to sesquiterpenes.
Live resin took Third Place with a ratio of 5.83.
Crumble landed in Fourth Place with a ratio of 5.76.
Rosin came in Fifth Place with a ratio of 4.91.
Dry-sift non-solvent hash took Sixth Place with a ratio of 3.97.
Only speculation can give a reason for these numbers. Despite the fact that dry-sift hash came in second place for total terpene content, it seems do have done the worst at preserving levels of monoterpenes. Curiously, this might not spell disaster for the aroma; quite the opposite. Dry-sift smells notoriously amazing, maybe these higher relative levels of sesquiterpenes such as caryophyllene oxide (which smells very sweet) lead to the incredible aromas.
On the other hand, its no surprise BHO does a great job at stripping terpenes from the flower as they occur in the trichome: butane molecules are excellent solvents. For a breakdown on the physical difference between wax (crumble) and shatter, read: Shatter Vs. Wax: What’s The Difference?.
People like to bash crumble because it doesn’t have the terpene levels of shatter, but the monoterpene-to-sesquiterpene ratio tells us that crumble has its own unique smell that can’t necessarily be compared to anything else.
(Photo by Lochfoot)