Because 80% THC wasn’t enough, the extract chemists have figured out a way to remove most of the waxes, turpenes and lipids that both BHO and CO2 extractions leave behind.
It’s called Crystalline.
It looks like kosher salt but it packs a wallop. This is as close to as pure THC that you can get.
Gold Extracts is one of the companies
selling 99.9% THCA
If you can remove enough of those terpenes, lipids and waxes you can selectively be left with either 99.9% pure THCA or 99.9% CBDA (based on the incoming strain characteristics). At this purity, you get just the pure crystal structure – no terpenes at all. This is almost no perceivable taste. Producers offer a unique way to combat this criticism by basically adding a drop of the extracted turpenes back on the crystals and what I initially thought wouldn’t work made a quick believer – it does make a difference.
So how do they do this? Producers of the different products like to veil it in secrecy (that way they can increase demand) but in fact, a couple of the methods are pretty well known (one is even patented) – but they all follow the same general scientific methodology.
The incoming extract is about 80% pure THCA. A solvent is added to that material (in some cases hexane and acetic acid, in other cases you can use an alcohol) and then that material is filtered and put in a rotovap to get rid of the remaining solvent. At this point the material will be closer to 90% region in terms of the molecules that you are targeting which makes it easier for the next step.
The next step is to use a practice called size exclusion chromatography or as I learned it, molecular sieve chromatography. What this basically means is that you suspend your solution something that is soluble to the molecule that you are targeting – in the case of THC you have the choice of a carrier oil or alcohol and put it through a porous material. Different molecules have different weights and will move through the porous material at different speeds. This means that we can target the exact molecular weight that we want to capture – you can use something called a Sephadex LH20 column (although there are many alternatives in the marketplace now).
Redissolve this mixture in methanol, filter the solution and rotovap to remove solvent. Redissolve this in pentane, filter and then then just a lot of rotavaping until you get crystals.
So, not really a secret but a long process – which equates out to a very costly product.
There shows promise as well in the field of dry column vacuum chromatography, which according to the author can support much higher volumes of 100 grams a day.