Let’s start with a simple question: what is a plant extract? A plant extract is a substance with desirable properties that is removed, typically by a solvent, from the tissue of a plant. Extracts have a wide variety of uses, from vanilla extract used in cooking to the aromatic oils used in essential oil diffusers. There are even extracts derived from cannabis, called cannabis concentrate that have been around since the 1940s. In fact, cannabis concentrate is the backbone of any vaping or dabbing experience. But in order to fully enjoy the essence of your favorite strain, you’ll need to add another crucial ingredient to the mix - that’s where terpenes come in.
A Delicate Balancing Act
There's no perfect way to extract terpenes from organic sources. As with most things, it's really a cost-benefit analysis - how do you eliminate impurities like fats, chlorophyll, and other plant metabolites without damaging the precious compounds you’re trying to preserve? There’s also the issue of time - the longer the process takes, the less efficient it is for commercial use and the more chances there are for impurities to work their way into the finished product. There are a whole host of methods and technologies that are used in pursuit of that goal. And their results generally fall into one of two categories - solventless and solvent-based extracts.
Solventless Terpene Extracts - Good for Avoiding Dilution
A solventless extract is made using the principles of heat and pressure. Here there are two methods: steam and hydrodistillation. Steam distillation involves suspending a basket full of raw plant material above a vessel of boiling water. As steam passes through the plant material, the lighter oils, which includes certain classes of terpenes, are drawn out of the distiller until they come into contact with a cooled condenser which liquefies the water and oils. The lighter oils float on the surface of the water and can be easily collected. Hydrodistillation is similar except the plant material is placed directly into the boiling water. The advantage of these methods is that, by not introducing any solvents (like butane or ethanol), there is no danger of diluting the extract with residual solvents. However, there is a downside which is that working at such high temperatures carries the risk of altering or destroying the terpenes altogether.
Solvent-based Extracts
Solvent-based extracts that are made with lower boiling points were developed to address this issue.
Butane Hash Oil
Butane hash oil (BHO) is a cannabis concentrate that is created through the use of butane and applied heat and pressure. The end product is a hardened yellow-gold substance often referred to as “butane honey oil.” It’s the most common solvent-based extract, as it produces a high yield in a relatively short period of time.
Butane hash oil can be understood as the end-product of complex process that extracts the THC content (among other things) from the raw marijuana plant. If you're interested in learning more about how to extract raw THC without using butane terpene extract, check out this which has all the info you'll need to get started. In the meantime, let’s a closer look at how to make BHO.
BHO Extraction
The butane extraction process entails placing the raw plant material into a glass container and shooting it through with a butane solvent. The resulting liquid is then put through the winterization process. This result is a refined BHO concentrate. Butane is also a non-polar solvent, which means that you can reliably extract terpenes from the plant source without also extracting impurities.
A Word on Butane Tubes
There’s a lot of misinformation out there regarding the safety of using butane tubes at home. A lot of this has to do with several well-publicized accidents involving amateur kids trying to make BHO at home with so-called “open BHO tubes.” As a result, CO2 extraction companies have financed a widespread campaign to demonize all things BHO. When done properly by trained professionals, butane extraction is run through a closed loop system, which means that all the butane that evaporates during the extraction process is recovered safely in a vacuum oven.
It’s very important to prevent it from contaminating the air, because it could result in an explosion. The numerous news stories of basement explosions caused by novices not using a closed loop system have seriously damaged butane extraction’s image in the marijuana industry and have led many companies to seek safer alternatives.
Supercritical CO2 - A Safer Alternative
One such alternative is supercritical CO2 terpene extraction. This process uses heat and pressure to turn gaseous CO2 into a supercritical fluid, which is a special state of matter that acts as a solvent for the plant material. This process of cycling the CO2 through the plant leaves produces a compound which needs to be refined in a process known as "winterization". Winterization removes the plant lipids and fats from the desired terpenes. CO2 is non-flammable, making this process safer than butane extraction. However, the refinement and winterization steps mean that more of the terpene profile will be lost in the process, resulting in an extract that will not be as potent as with other methods.
Live Resin - The Advantages of Frozen Concentrate
For a more potent end product, live resin is a popular alternative. Live resin is a type of concentrate that is manufactured by keeping the plant material frozen at subcritical temperatures throughout the process. In other kinds of concentrates, like wax or shatter, the drying and curing process involves the use of heat, oxygen, and physical disturbance in order to remove moisture and chlorophyll from the plant before extraction.
Unfortunately, these factors have a highly destructive impact on the plant’s terpene content. Live resin is therefore unique in that the plant is kept frozen, preserving its aromatics. The end result is a concentrate that has a greater and more complex terpene content than most BHO and supercritical CO2 extracts. The only downside is that, as with all concentrates, the amount of time it takes to produce.
Breaking New Ground with Ethanol Extraction
This takes us to ethanol extraction, a new method still under development that is safer than butane and more efficient than live resin. While ethanol is a tried and true solvent that has been used to make plenty of other substances (from hemp oil to food flavoring) it hasn’t yet penetrated the extract market the way these other methods have. And that’s because its greatest strength as a solvent is also its greatest weakness. Ethanol molecules have both polar and nonpolar ends, allowing them to bond with a wide variety of molecules. This makes ethanol effective at drawing out cannabinoids and terpenes from plants, but it also makes them effective at drawing out impurities as well. Chlorophyll, lipids, and other components can get into your oil, giving it a dark complexion and even imbue it with a bitter, grassy flavor. However, new extraction technologies are being developed to deal with this problem. Many ethanol extraction systems now operate at cryo temperatures so that the plant material can be sprayed with ethanol at its freezing point. There is also micron filtration, which is a cutting-edge method of filtering impurities out of the extract. This allows users to skip the winterization process, making the whole process cleaner and much more time effective.
Admittedly, this isn't a simple process. If you have custom requirements True Blue can provide wholesale terpenes so you can skip the extraction process and let us do the hard work.
Why Worry About The Smell And Flavor Of Your Cannabis?
At this point you may be wondering why the flavor and smell of your cannabis should concern you to the point that you actually consider altering your growing process. As any home grower knows, it can be hard to zero in on the exact process that produces healthy, potent strains. Most growers would rather stick to a reliable process, rather than risk an unsuccessful crop. Here’s why we think it’s worth re-evaluating that process with taste and smell in mind: your customers want it.
Whether you’re growing medical marijuana as a caregiver for multiple patients or selling it to recreational dispensaries, your product must have a potent flavor and smell to set it apart from the rest. Consider what people do when they’re shopping for flower -- they open the jar and take a big whiff. If your buds aren’t pretty and the scent is lackluster, the perceived quality of your product will fall drastically in the eyes of potential customers.
Another reason to worry about the taste and scent of your cannabis is that they are directly correlated with the medical value of your plants. Terpenes are responsible for a given strain’s flavor and scent profiles, and are rich in their own therapeutic qualities. The presence of more of these essential oils directly translates to the presence of more medicinal benefits.
Terpenes Are The Secret To Dank Marijuana Flavor Profiles
Terpenes are the key to cannabis plants having stunning scents and fantastic flavors. As a strain grower, you have the power to influence the level of terpenes present in your plants.
Since our sense of smell is deeply connected with our sense of taste, how your cannabis oil smells will have a serious effect on how people perceive its actual flavor. So the question becomes: how do you flavor weed? Well, in order to do this, you have to wait until the raw plant material is processed into cannabis oil. Once you’ve distilled the THC, CBD, and other base components into a concentrated liquid, you can introduce external oils.
Strain Flavor Tips To Try & Mistakes To Avoid
Things you’ll need to produce plants with high essential oil levels (stronger scent and flavor profiles):
- Specialized nutrients and soil supplements - Don’t use “bloom” nutrients in the veg stage. Try to avoid chemical nutrients in favor of fertilizing agents made from organic sources (think kelp, bat guano, and worm castings).
- Use strong grow lights that deliver UV-B - While most growers flower their cannabis plants under HPS grow lights, research suggests that UV-B lights can enhance trichome production and strain smell. “Supplementing your flowering plant with UV-B light may increase the potency and smell production by triggering a natural stress response,” explains Grow Weed Easy.
- Watch temperature and humidity closely - Indoor cannabis growing often feels like a greenhouse operation, but there’s strong evidence to suggest that keeping the environment cooler and drier actually enhances essential oil production in your plants. During the day, try to keep grow room temps at 80 degrees or below, and keep the nighttime temperatures 5 - 10 degrees cooler. Humidity should be kept “around or under 50% relative humidity throughout the flowering stage for the best terpene production and overall plant growth,” GWE continues.
Enhance Your Marijuana’s Flavor With Terpenes From True Blue
Focusing on terpene production can be a little intimidating at first, and you’ll likely go through some trial and error. Don’t worry! Strain flavor can always be enhanced after harvest with the help of terpenes from True Blue.
Take a look at our full selection of fun flavors