Thursday December 9, 2021
Diamonds. Throughout history humans have coveted them, from killers to kings, derelicts to debutants. Diamonds bond together our sacred unions and cut apart the world’s hardest materials, representing the utmost finery and precision. It’s only recently that people have started smoking them.
Of course, no one is going to try to smoke grandma’s jewelry, but the crème-de-la-crème of cannabis does happen to come in a form quite familiar to the upper crust: Glassy THCA preparations, commonly referred to as “diamonds,” are some of the finest concentrates available.
THCA diamonds are crystalline structures created from extracted cannabis plant matter containing ~99.96% purity. To the initiated, diamonds are believed to be one of the finest smoking experiences available, unrivaled in purity of taste and effect, but understanding these coveted glaciers often requires some explanation. For insight on this piece I consulted with seasoned grower, extractor, and budtender Matt Gosling. Follow along as we delve deep beneath the surface of the new wave in concentrates.
Concentrate Diamonds and Crystallization
Referred to as “diamonds” for their appearance and regard, Matt informed me that in reality what we are discussing is crystals.
Although THCA diamonds can be harvested through a variety of methods they all follow the basic principles of crystal formation, the same one you might recall from making rock candy as a kid.
When making any crystal, the thing we want to make crystals out of (the solute) is dissolved into a medium (the solvent) to create a liquid solution. The solvent is then altered through heat and/or pressure to stuff more solute into the solvent than it would normally hold. That extra amount is then added, creating a super saturation (bartenders do this every day to create simple syrup).
Once a super saturation is achieved, the solvent and any other impurities are then drawn out of the super saturation through augmenting of volume, heat and pressure. If we recall high school chemistry, this is possible because unique molecules act differently, with their own evaporation and freezing points. With the other elements in the super saturation purging out, this leaves the solute nowhere to go, and coaxes its molecules to cram together. When molecules cram together, they seek out the most efficient structure of bonding, which for many molecules is a rigid structure, resulting in – you guessed it – crystals!
Matt further explained that when working with something like sugar or salt, the process of crystallization is very simple, because the elements used are extremely stable, have few impurities, and have large ranges of stability in regards to temperature and pressure change.
It’s more difficult to make THCA crystals because THC is not as stable and will change with very little variance to its conditions (recall that THC will degrade into CBN at even room temperature over time).
Additionally, on the cannabis plant matter are a host of compounds that need to be separated out from the desired THCA. There are waxes, terpenes, esters and other compounds to consider, many of which have very narrow evaporation ranges. If any of these elements is extracted improperly, outside of its precise range of temperature and pressure, it can ruin the whole batch being processed. The extraction steps are also important in their own right, because this is how terpenes are isolated, and are needed to create “sauce,” a preparation of both THCA crystals and high-terpene extract.
Into the Mines: A Variety of Diamond Harvesting Techniques
Within the concentrate community, there seems to be two major ways of going about THCA crystallization, mechanical and chemical. Though each is doing the same essential process of creating a super solution and then separating off the parts until only THCA is left, they are achieved through quite dissimilar methods.
The quicker, more popular method involves stripping the cannabis plant matter of trichomes using a solvent such as butane or propane, then subjecting the resulting mixture to multiple chemical baths and rounds in a heat/pressure chamber to purge out the solvents. This method requires a good amount of industrial chemistry equipment and precise operator knowledge to work, but is capable of making large batches with quick turnaround.
The precise nature of the process has resulted in many extractors treating this knowledge as a guarded secret, often speaking in code on Internet forums to keep their one prized element of the puzzle a secret from others. One such version has even sought the protection of a patent in the US. The downsides of this process are a hefty startup cost for equipment and if anything goes wrong, you risk contamination with a harsh chemical solvent.
Alternatively, it is possible to achieve these steps through mechanical means. Instead of chemical solvents to strip plant matter, the bubble hash or rosin is used as the starting material, harvested through filter bags and ice baths. Rosin presses take over the dual roles of both pressure chambers and chemical separators to partition out the individual elements of the hash. Instead of different chemical properties to address each stage of separation, the presses are applied at varying degrees of temperatures and pressure to partition out the components.
Purging chambers might still be utilized at different stages, and during the end process to aid in crystal formation, but regardless, this method remains free of chemicals. Nothing needs to be “purged” aside from the undesirable elements already present within the plant matter itself. This method can require a bit more time and care, some feel it offers a more bespoke, higher-quality, though potentially more labor-intensive, product.
“What you get out is what you put in”
Matt relayed to me a seemingly endless list of tweaks and hacks to the basic crystallization process that many claim to be the key to giant glaciers of impeccable quality. However, in the end, he asserted that the best diamonds came down to two things: quality of the starting product, and the attention given along the way. If you want the best, seek out those who care.
Have you dabbed THCA diamonds before? Share your experiences in the comments below!