Some cannabis concentrate companies either grow their own or partner with growers. In either case, you can either procure fresh or dried cannabis.
This is an important choice. You can choose to partially cure the cannabis or you can use fresh flowers. what you decide will determine costs, and the amount of pre and post processing you may have after the initial extraction takes place.
Lets look at the considerations – and then I can tell you what my choice would be.
Fresh flowers are rich in volatile terpenes that have only just started their degradation process. All terpenes start to vaporize at different temperatures. The most volatile among them are what gives fresh cannabis that smell that fills a room. If you have ever been near a cannabis flower in full bloom, you know that smell I mean.
These terpenes start to boil off at around 70F. When you dry or cure cannabis, you start to lose a whole lot of terpenes that boil off at 80F-100F.
If you use fresh flowers, there will be less of a chance that any small plant material will make it into the final extract.
- transporting fresh material is very pungent.
- fresh material is very bulky – it hasn’t lost it’s water weight.
- terpenes will start to degrade quickly so fresh material should be harvested and used within 24hrs.
- fresh material will have a much higher water weight that will have to be removed post processing.
- the end resulting extraction will be more sticky
- there may be a slight decrease in yield
In order to use fresh material it is always best to flash freeze the material. This will make the trichomes more brittle and apt to separate from the plant easier.
Dried material is a know quantity. It is immediately ready for grinding and loading into the extractor. It is less bulky than fresh material and can be stored easier.
Cured material will have already started the process of converting THCA to the psychoactive THC. Which if you are creating concentrates that is not something that you are too concerned about. Because you can expose more surface area to the solvent, your yields will be a little higher than if you were using fresh flowers.
- Lose some of the taste once some of the turpenes have boiled off
- Possibility of plant matter making it’s way to the extract
- Have to properly store the dried material and over time it will lose some potency
So what is my choice?
Even though you get a little bit less those volatile turpenes that get lost through drying really makes the taste of the final extract change, my choice would be to use fresh flowers that have been flash frozen within 24hrs of harvest.
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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.
On the shelf of all dispensaries these days are a series of products that most cannabis users have never tried. They go by weird names like budder or wax.
Just what are cannabis concentrates and how does it differ from regular marijuana? Is it stronger and how is it made.
First a bit of bio-chem background. Marijuana is a collection of 3 major chemical types
- Tetrahydrocannabinol (Δ9-THC) – This is the main psychoactive ingredient in cannabis.
It has two major related substances including THCA which converts to THC when heated. This is what bonds to the cannabinoid receptors in the brain and is what gets users “high” (and paranoid…but more of that later)
- Cannabidiol. The two other major compounds found in cannabinoids are cannabidiol (CBD) and, once a sample has been aged, cannabinol (CBN). These are compounds that have been studied medicinally and have been shown to have medical benefits as far reaching as reductions in symptoms related to anxiety and nausea to seizure disorders. There are about 60 other compounds in the cannabinoid family that will reveal medical properties for years.
- Terpines – this is the mixture of about 60 or so different compounds that produce that unique smell of cannabis that can range wildly from strain to strain. They are only present in small amounts. One strain can smell of blueberry while another smells like lemon while yet another smells like pines. Alpha-Pinene and Beta-Pinene are what gives some strains that pine smell. Those terpines have properties as an antiseptic and memory retention but the neat thing about them is that they bind to the same receptors as THC does in the brain and are thought to partially counteract the effects of THC
Okay, chemistry lesson over. Now on to concentrates
Since the 70’s, cannabis growers have been breading plants to have more of the characteristics that users want to see – namely THC. It is common to see strains with THC upwards of 23%. What concentrates do it take it to the next level and after processing the cannabis can see THC levels as high as 80-90%.
How to they do that?
There are a couple of different methodologies for creating concentrates but I’m going to focus on producing concentrates with a solvent – Butane and CO2.
In the most simplistic terms – a solvent is used to dissolve the desired molecules (namely THC and Cannabinoids) and then a process is used to get rid of the solvent – leaving behind as much of the desired THC and Cannabinoids in a concentrated form.
A common method to do this is by using butane. Butane as a liquid is soluble for the THC and Cannabinoids to grab onto and ride away from the rest of the plant material. After the liquid leaves the butane chamber it is left so that the butane will evaporate. There is some risk as many brands of butane contain impurities that will remain in the end product and can leave a distinct taste but it is inexpensive and how the majority of grey or blackmarket solvent based concentrates are made.
Another method (and my preferred) is by using CO2 as the solvent. CO2 under pressure and at certain temperatures can be tuned to remove different profiles including THC and Cannabinoids and is a liquid. CO2 is food safe and is a process used widely in the food industry for decaffeinating coffee for instance.
Both of those methods produce a result that is similar – An extract from the marijuana plant that is almost entirely made up of THC with a few fats, terpenes and waxes that remain. Here is where the post processing takes place and differentiates Shatter from Budder.
Budder takes this concentrated material that you’ve extracted from the plant and lets it dry. As the gas escapes it creates honeycomb like features in the concentrate when the THC molecules start to crystallize. Some producers will even stir the mixture to add in additional air bubbles.
The consistency of the budder will depend on a few things including the texture of the incoming oil and if the process to remove contaminants (in the case of Butane you are removing Butane molecules and in the case of CO2, you are removing water). The end product can resemble a crumbly material (often called crumble or honeycomb) or a gooey wax called budder. Budder can contain up to 80% of the material being THC and Cannabinoids (the amount of each is dependent on the strain but most budder around 70%-80% THC and less than 1% CBD.
Shatter takes this product that remains at the end of the extraction process and uses a couple of different methodologies to remove the waxes and lipids that remain. This process is called winterization. It involves dissolving the extract in ethanol. Once the liquid is cooled, it will precipitate out the unwanted waxes and lipids leaving you with a pure cannabinoid (THC and CBD)/terpenoid mixture . The end product is placed in a vacuum oven to remove the remaining moisture and what is left is a clear sheet of amber that will shatter at room temperature. THC levels in Shatter can reach in the mid to high 80s.
Those are two of the major cannabis concentrates that are seen in the market today. Next time I will write about the different types of oils that can be formulated from cannabis extracts.