As Rosin-tech sweeps the United States of Dabs, leaving every stoner’s buds flat and their sisters flummoxed as to why their hair smells like pot after straightening out their curls, HIGH TIMES has collected enough samples in its Cannabis Cups to make some real determinations about what rosin really has to offer. Sit down, squish a few buds and check out what science has to say about the rosin you know and dab.
For those who may not be familiar with rosin, don’t worry; the concept of rosin is much simpler to explain and understand than butane hash oil, or of course, super-critical fluid extraction hash oil. Rosin-tech involves the use of a hair-straightener to press cannabis oil right out of a bud or piece of hash stuck in a piece of folded parchment paper. Heat and pressure melt and push the oil right out of its natural location, the trichome. To really get a feel for the original rosin technique, check out this step-by-step.
Rosin quickly gained popularity for its ability to turn less-than 5 Star dry-sift into pristine, full-melt dabs at an acceptable yield. In California people are practically wading in hash deemed by the connoisseurs to be less than desirable, yet the real crème-de-la-crème is so volatile it pretty much dabs itself. California’s abundance of hash is coupled with its abundance of flower, and it didn’t take long for even the first rosin-maker to put a nug between some parchment paper and squish it (I’m talking about a timeframe of minutes).
Between the past few Cannabis Cups, HIGH TIMES has amassed a sizeable sample pool of rosin entries. Rosin averaged with an average THCTOTAL content of 76 percent. For comparison, other non-solvent hashes (bubble or dry-sift) from the same Cups average at 69 percent THCTOTAL, while BHO dabs averaged at 75 percent.
When it comes to terpenes, rosin entries had an average of 0.66 percent terpenoids by mass. Other non-solvent hashes average at 0.75 percent terpenoids, and solvent-extracted oil took the cake with 0.77 percent.
We know what you’re thinking about the 0.77 percent average of the BHO terps: one (or a few) of those solvent-extracted entries are reconstituted with outside terpenes (cannabis or not), inflating the average. You’d be wrong thinking that, all the entries were laid out on a table to observe any outliers and assure they didn’t skew the average. As it turns out, no outliers existed and all of them were perfectly compliant with Cannabis Cup rules and regulations.
To measure the amount of decarboxylated THC, I devised the “decarboxylation percentage,” defined as the percentage THC / percentage THCA multiplied by 100. BHO entries had an average of 2.7 percent (for example, a median entry has 2.1 percent THC and 85.5 percent THC). Non-solvent hashes had an average of 6.6 percent, and rosin had an average of 19.3 percent, significantly higher than that of the other two methods.
Obviously, the heat involved in pressing the rosin decarboxylates some of the THC, although it’s interesting to note that these decarboxylation percentages improved as time went on, people got better at making rosin!
By using more pressure and less heat, extract artists have been able to make rosin with a higher ratio of THCA to THC, why is this better? THCA is a solid, THC is a runny, sticky oil. Extracts with lower percent decarboxylation handle much more easily, giving a more manageable and desirable product.
All in all, rosin has incredible lab results given the simplicity of the method. For all you home extract artists, you don’t need a closed-loop system and a static-free room with an air-exchange per minute to make good oil safely. Heck, you don’t even really need a professionally made rosin press, just grab some parchment paper and the cheapest hair straightener you can find and you’ll be making dabs on dabs.