And is it safe for our bodies and the environment?
How do you get cannabidiol (CBD) off the plant and into products? It all starts with extraction. We can debate the efficacy of full spectrum oils versus water-soluble nanoparticles, crude or isolate until the cows come home, but really, the first step is coaxing cannabis to give it up.
For starters, I’d like to say I’m no scientist. I got A’s in high school chemistry (which was good enough to woo my now-husband - or maybe he just needed to copy my homework?) and I now spend a bit of time in my day job with applied science in material specification. All that to say, I know enough to be dangerous and I’ve had a few very good teachers on the cannabis side as we have started a farm and developed products for both inhalation and topical applications. For me to really be able to understand a topic, I need to break it down into manageable chunks and easily categorize the options, each with their pros and cons. So here’s my off-the-cuff introduction to CBD extraction for newbies in an effort to make you a more informed CBD consumer in this burgeoning industry. I’ll also try to draw a few conclusions on each method's potential for harmful toxins and impact on the environment since both are considerations that are near and dear to many of us.
To start, why do we need to do it at all? Why can’t we just chew the raw plant right out of the field or dump it into our cookie batter and expect the healing properties of CBD? Why, historically, has hemp or cannabis been smoked? Hint: heat. Because THC and CBD (and other cannabinoids) exist in the world in two formats: acidic and activated. The tetrahydrocannabinolic acid found in the raw plant needs heat to turn into the activated forms of CBD (or THC) we know and love. This process is called decarboxylation (or heating to the magical temperature at which it releases a carboxyl group). It’s a fancy word, but really just means that once the right heat has been applied, it’s ready to rock.
There are really two big buckets when it comes to extraction: solvent-less and solvent-based. Solvent-less extractions are exactly what they sound like: no solvent needed. What’s a solvent, you ask? A solvent is typically a liquid that is used to dissolve another substance and create a combined solution. Solvent-based extractions rely on the solvent itself to extract the good stuff and then ultimately be removed from the final product.
When we don’t use a solvent, we rely on centuries-old techniques to get cannabis into a more concentrated, usable, and activated form. Heat and pressure can coax the cannabinoids and terpenes out. You may be familiar with end products like kief, hash or rosin? All solvent-less. Alternatively, you can use oils and butters under heat to attach to the lipid (fatty) structure of the cannabinoids and create a concentrated end product great for baking or topicals. Coconut oil, olive oil, butter or ghee are all great extractors for different end uses in their own right.
Can I do it at home? Absolutely. And people have been doing it for centuries. At Hatshe, all of our recipes started right here in my kitchen with a double boiler (heat!), some olive oil, and some trimmings from our farm. (Isn’t she pretty this time of year?)
How efficient is it? These simple extraction methods tend to be the least effective of the extraction types discussed here at getting all the cannabinoids off the plant but, depending on your end use, the strain you are working with and it’s inherent potency, it may be plenty.
Is it good for me and the planet? This question is never easy to answer in any context, but I can confidently say yes for the double boiler method or pressed (using pressure) extractions. There’s minimal waste in either process - just some plant material that can be composted- and the end result is stable and safe enough to be in your kitchen.
Solvent-based extractions fall into a couple of different categories: butane, CO2 and ethanol. This is where it gets a little more complicated - but we’ll try and keep it light. Of the three main extraction methods, none is perfect, but each has their place.
Butane can be blended with hexane or propane to create a light hydrocarbon extraction. The benefit is that you can remove some of the unwanted material (like dissolving resins, waxes, and chlorophyll) before grabbing onto the cannabinoids and terpenes. The most common products on the market using butane extraction are shatter, budder or wax - highly concentrated material meant to be inhaled.
Can I do it at home? Honestly? No. You’ve heard of propane - right? Fairly flammable and great for the BBQ, but maybe not for a home extraction project. It can be fairly safe if done in a lab with proper maintenance, oversight, and equipment in a closed-loop system, even with the high combustibility. The opposite of the closed-loop system called “open blasting” can more easily result in those lab explosions that make the news.
How efficient is it? Much more efficient than solvent-less. Estimates are around 65% to close to 90% potency on finished oil. This may seem like a wide range, but remember that cannabinoid concentrations in the plant material can vary widely and extraction is all based on what Mother Nature provides to start with.
Is it good for me and the planet? Residual solvents can remain in the extracted oil, but can be removed through distillation. There are bad actors out there using low-quality butane which can contain harmful toxins that are dangerous for human consumption.
CO2, in its supercritical state (when cooled and pressurized), can pass through the cannabis plant as a gas. The use of a process called “winterization” uses ethanol, menthol or isopropanol to remove the waxes and chlorophyll. Distillation, again, further removes any residuals.
Can I do it at home? I’m not really set up for it at my house, but there’s nothing inherently dangerous about the process.
How efficient is it? Pretty good, but the lowest potency of the solvent-based methods. Estimated at around 50-65% potency in finished oil. CO2 extraction can bring along unwanted waxes and other plant fats. Removing these can also remove some of the wanted cannabinoids and terpenes and can be a fairly lengthy process.
Is it good for me and the planet? Carbon dioxide has rightfully earned a bad reputation, but it’s still pretty safe to have around your body in general. On a large scale, no, we don’t want more CO2 let out into the atmosphere. All told, though, it has a low toxicity and relatively low environmental impact as an extraction solvent.
The final solvent-based method uses food-grade ethanol passed through plant material which grabs the terpenes and cannabinoids in their original chemical ratios including some (and other phytochemicals) that the other processes remove. Remember that we don’t know what we don’t know about all the components of cannabis that have healing properties since research on the topic is so new and so recently emerging from the shadows. We do know that Mother Nature was onto something in cannabis and we do see improved efficacy from the entourage effect. Ethanol extraction does grab some other compounds along the way that can then be separated and removed via winterization. Ethanol also easily evaporates leaving little to no trace in the finished product. It’s highly efficient in that plant material can be run through the process (with the same ethanol) multiple times leaving little on the plant.
Can I do it at home? Do you have a rotovap? I don’t. Ethanol is pretty flammable as well. I’d leave this to the certified professionals.
How efficient is it? Again - pretty good. Estimates put this methodology around 65-85% potency on the finished oil. It’s great for creating full spectrum oil since it does grab all the unidentified good stuff along the way.
Is it good for me and the planet? The FDA certifies ethanol as GRAS (Generally Regarded As Safe) and it’s commonly used in food and medicines as a preservative. Labs can re-use ethanol and the remaining plant material can be composted so there is little waste. Some residues such as waxes or chlorophyll can remain in the oil, but like we said, can be removed during winterization and typically don’t make it to the consumer through post-processing.
Phew. Thanks for staying with me; I know it can be a daunting and overly-scientific topic. Hopefully there were a few nuggets in there for your journey to being an educated CBD consumer.
What do we as Hatshe, a consumer products company, prefer? Obviously, I love a good slow-cooked extraction to get back to where we started, but since it tends not to be the most potent of the choices out there, we at Hatshe have chosen to use ethanol-extracted full spectrum hemp oil because of our dedication and experience with full spectrum products. As of this moment in the evolution of cannabis science, ethanol extraction gives us a full array of cannabinoids, terpenes and other phytochemicals in the closest ratio to the way they occur in the plant and, in our experience, gives us better results.