For a little while now I’ve been working on constructing an ethanol extraction process to craft something similar to the High-Terpene-Full-Spectrum-Extracts (HTFSE), High-Cannabinoid-Full-Spectrum-Extracts (HCFSE), Sauce, Sugar and such that would rival the appeal of other high-terpene collection efficient extraction methods. The good news is, when it works it’s easily the best Ethanol Hash Oil (EHO) product I’ve ever made. The bad news is, it’s frustratingly unreliable.
Working with ethanol extraction at cold temps to make EHO has some very strong advantages like being very clean, extraordinarily smooth and high potency. The often heard complaint though is that ethanol extraction appears to have a lesser aromatic terpene profile. While the actual overall terpene content isn’t vastly different compared to other forms of extraction the lighter aroma gives that impression. I’ve always been of the opinion that the advantages of ethanol extraction far outweigh that single minor disadvantage, but now that disadvantage is gone and these extractions are the next level for EHO.
The process has been successful with THCA, CBDA and CBD extractions. The crystalline formation tendencies of the decarbed cannabinoids THC and CBD are opposite in nature. Where THC will not form into crystalline structures, CBD is very prone to do so. All this means is this process should be workable with anything except decarbed THC extractions.
I began by working with “jar tech” protocols that are well established post-process extraction methods used in hydrocarbon extraction and rosin. The term “jar tech” refers to using a jar as a vessel to achieve an end goal. In this post I concentrate on crashing cannabinoids into a crystalline lower layer formation with a terpene rich fractioned layer above. Each of the two layers have both cannabinoids and terpenes but the weighting of each differs greatly. The upper terpene layer is heavy in terps with 40%-60% cannabinoids and the lower crystalline layer is around 90%+ cannabinoids.
Jar tech with hydrocarbon extraction provides a great environment for easy supersaturation due to the solvents used and the cool kids can easily make large crystalline rock-candy shaped “diamonds.” Unfortunately, ethanol makes this much more difficult and without resorting to hexane or pentane washes so I’ve somewhat resigned myself into accepting not being able to compete with the vanity level of glorious big and chunky diamonds, but being happy with the same cannabinoid content (or more) and amazing terpene component I would argue is very competitive in the banger.
Writing a reliable SOP for this process using only at home safe tools has been problematic because the outcomes have been unpredictable and frustrating. What I’m sharing here are the approaches I used, what I learned, and the results achieved. Some attempts were more successful than others but all provided some insight into the process. It’s my expectation that people will find things that I missed that will improve the process, I welcome that information and I would very much appreciate any input being shared in the comments section.
The Golden Rule of extraction, “fire-in, fire-out,” is very important with this process because using very good material is really the only way to achieve the high terpene extraction that makes separation possible. I used very nicely grown and cured flower (Snowcap, Glueberry, Bubba Kush) that had the RH of a good cure that was still a little squishy. People often say, “the dryer the better,” but the truth is that’s not always the case. Excessive drying helps to eliminate moisture pickup during the extraction but it also leads to larger terpene loss in the flower. Some material moisture risk can be mitigated by using very low processing temps for the extraction, but there’s a limit to how far this will work, using fresh material isn’t possible because there’s just too much wet plant material involved. Alternatively, using fresh freeze-dried material can be amazing and take things to a new level.
For processing with ethanol the flower can be left whole and intact for the least risk of picking up chlorophyll, but the consequence of doing so when working with low temps is a very low yield. To achieve a more attractive yield, prepare the cannabis by breaking up the flower by hand, causing the least amount of damage possible that will allow ethanol to access and flow freely over all material surfaces.
To make the cleanest extraction dry ice was used to cool the cannabis and 190-proof food-grade ethanol separately to at least -50°F overnight. Once at temp the cannabis and ethanol were combined to soak for 1-hour with agitation every 15-minutes. At these low temps, with great material in good shape, the soak could have been extended quite a bit but I wanted to play it safe. After soaking, the contents were strained with a 40-micron nylon mesh sheet, then filtered twice with a Buchner funnel using a 25-micron first and finished off with a 3-micron filter paper.
I use the EtOH PRO by ExtractCraft for the ethanol recovery phase of larger batches and the Source Turbo for smaller ones. I stopped the ethanol recovery when the concentrate was still quite liquid, just before the viscosity would change to oil. The concentrated liquid was poured onto a silicone mat (ideally with no logo or writing on working area) with the corners clipped up to make a boat and readied to air-dry.
The liquid should be in a larger thin layer, as opposed to a smaller deep layer, so the residual ethanol can evaporate more efficiently. For even progress the layer needs to be flat with an even depth. If a skin-like film forms over the surface mix it up gently so the ethanol evaporation isn’t inhibited. Lastly, the environment is important and needs to have controlled humidity and ambient temp. High humidity or low temps work against the evaporation process. After a day or two the oil should be a heavy and thick consistency ready for the next steps. There will be a residual ethanol component at this point but that can be worked on with purging later in post-processing if necessary.
For a jump start on the crashing process the extraction can be “seeded.” This means that already crystalized forms (“seeds”) are added into the extraction to foster crystalline growth around them. You will often get lucky and there will be a some crispy layers on the periphery of your extraction as it air-dries. If you’d like to be more proactive to make sure you have plenty, take a second mat and smear an ultra-thin layer of the extraction on it. After letting it air-dry into a very thin shatter it can be scraped up and combined with the main load for seeding in the next step.
JAR TECH or FLAT PACK
This is where things begin to take on a life of their own and may bring either beautiful treasure or frustration. Regardless of what happens, there’ll be some form of terpy goodness waiting for you in the end even if it doesn’t crash the way you want it to. Something special happens with the terpenes as they set and fraction away from the forming crystalline structures. I don’t know exactly what happens, but I’m inclined to believe it’s similar to what happens when good flower cures, hashish ripens, and wine ages. Whatever it is, the terpenes become deeper, more intense and are downright succulent.
The term “Jar Tech” comes from using a canning jar as the vessel to hold a concentrate and post-process in the jar for a desired outcome. The ordinary canning jar is probably the most used tool I have in my bag of tricks; I use them for storage, washes, flower decarb, jar tech partial and full decarb, CWD, infusion, catching lightening bugs, and in this case to make sauce. For volumes too small for the surface area of the smallest canning jar I’ve had success with small 6 ml size glass containers as well.
Inconsistencies in outcomes are influenced by differences in strain characteristics, material harvest, material handling, material storage, extraction execution, environment, and a host of other factors. Some extractions will sauce right before your eyes on a mat during post processing whether you want it to or not, and other samples won’t crash no matter what you do. Here are the different considerations I’ve been working with in different combinations. You can experiment to see what works best for you.
Loading the Container: I work with canning jars of the appropriate size to fill approximately 1/3 to 1/2 of the container. I believe having more surface area is more important than having depth, which is why commercial operations use flat Pyrex dishes with larger batches. After the extraction has been loaded, introduce any crystals intended to be used for seeding.
Freeze or Don’t Freeze: Starting with a freeze phase is intended to instigate initial crystallization development. I’ve had success with both freezing and without. If you go the freezing route give it at least one day and see how it goes. I’ve heard of people using dry ice temps for this but I haven’t had the chance to test that out yet so I’m not sure if there is a benefit to it or not.
Sit and Crash: This is the sit and wait period that may take a handful of days or a couple months to get the amount of crashing you desire, or, it may not work at all. I have more work to do in this section, but up to this point I’ve found that allowing the extraction to crash in an ambient temp between 50°F – 70°F has worked best for me. Most jar tech with other extraction methods add low heat, but every time I’ve added even very low heat to ethanol extraction jar tech it’s had adverse effects and melted any crystalline formation present. (There may be a secret I’m missing to successfully adding heat here and if anyone knows please reach out and point me in the right direction)
Crashing is a very slow crystal growing process so moving the jar will disrupt the in-progress development and is best to avoid disturbing the jar at all while it sits in a dark area away from any UV exposure. As it sits, back pressure will grow and is said to be necessary to keep the crystalline formations pushed to the bottom, however, it can also be counterproductive at a certain point so if you see the formation progress stop, gently unscrew the lid to release the pressure, secure the lid again, let sit and see how it goes.
Harvesting Contents: If things went right you should be looking at a nicely formed crystalized layer on the bottom and nicely separated liquid terpene layer setting on top. A great option is to use it as-is with the glorious fractions and deliciousness, but if you want to post process or manipulate the concentrate form the contents will have to be harvested from the jar.
In addition to the uncertainty of an extraction crashing well or not, harvesting the jar contents can also lead to frustration because when the terp layer is mixed into the cannabinoid layer again, it will become more of a soupy slush. It’s not the end of the world and I do this intentionally to purge into an amazing sugar wax with all the benefits of the lifted terpene profile.
Instead of leaving the jar as-is or harvesting the contents together, the terpene layer can be gently poured off to purge separately, then the cannabinoid layer sealed again to set and possibly foster further development. If separated there are a couple options for end use. The terpene layer has a lower cannabinoid potency but can be used for amazing vape pen cartridges and the cannabinoid layer used for dabs. The other option is to reintroduce the two fractions back into a jar after purging separately and have something similar to the sugar wax mentioned above but layered in the jar with the cannabinoid layer on the bottom and a more terpy layer on top. It will resemble the original jar organization but much tighter.
There are a few options and all of them are winning.
Adding Terpenes: The end product will be incredibly and deeply terpy so adding additional terps may seem unnecessary, but I often do. When I end up with 20+ grams of the same concentrate, no matter how good it is I get bored pretty quickly. I usually partial off the concentrate into 1-2 g containers so when I get bored I can add 1-2 drops per gram of flavored terp profiles (I only use the brand True Terpenes) to make it a whole new and exciting thing again. With the smaller 1-2 g sample sizes I can customize each container with something different for myself or have a great variety when entertaining friends.
This is something new I’ve developed myself and have been toying with on small batches of 5–10 g. It’s provided nothing short of amazing results in some cases and absolutely nothing in others. The idea is to provide more surface area for the cannabinoids to crash/sugar onto by putting a thinnish layer of a clean, high terpene extraction on a silicone mat (no logo or printing on the working area) then folding it into quarters and clipping to hold flat. I place the quarter-folded and clipped mat into an airtight case and leave undisturbed at room temp. Good results have fully developed in as little as 1-week, as long as 1-month or not at all. I’m not convinced this is a great idea yet, but it’s provided results surprising enough to peek my interest and share with you to experiment.
* Some people don’t like silicone so this won’t be for them. I’ve tried with parchment paper a couple time and have not been able to recreate so far.
POST PROCESS PURGING of JAR TECH or FLAT PACK
Following jar tech or flat pack the need for further residual ethanol purging is going to depend on, how much purging was accomplished before loading for crashing and personal preference. Obviously, if you do a pretty thorough purge before loading the extract to crash there won’t be much to purge. In fact, as the extract sits and crashes ethanol will be evaporating out the whole time so there will be less residual ethanol remaining in the end. Personally, the residual food-grade ethanol, within reason, doesn’t bother me so much. If you want to purge you can allow the extract to air purge once again or use a vacuum chamber/oven but be careful with the heat.