In this second edition of the Hemp Lab Series with our Hemp Advisor, Drew Ford, we dive into the different hemp extraction methods and the resulting product outputs. We weigh up the pros and cons of the different approaches and we look at the range of products like broad spectrum CBD, full spectrum CBD, and CBD isolate. Spoiler alert: we recommend customers pick products which use broad spectrum CBD oil from either alcohol or CO2 extraction.
Why? Because these products exclude THC and still contain the valuable hemp plant contents alongside the CBD. Early science tells us broad spectrum, thanks to the entourage effect, could be more effective than CBD isolate. The downside is it is more expensive than a CBD isolate product. However, you get what you pay for!
Typically carried out utilising butane or propane as the extraction solvent, hydrocarbon extracts have garnered significant popularity among the recreational cannabis users in the United States. The cannabis industry primarily use hydrocarbon extraction as it produces a high quality product that can be easily smoked. Because of the particularly low boiling point of hydrocarbon gasses, the solvent is fully removable from the extract which allows for the best preservation of terpene content and hence flavour. After all, it is the terpene profile which differs by strain and is what gives each strain its unique taste.
Unfortunately, hydrocarbon extracts do not offer the same medicinal efficacy as other extraction methods, which we will address later. Due to the low amount of medicinal benefit, lower throughput, and significant working hazards, hydrocarbon extracts are not common for hemp. Instead, CO2 and ethanol have become the major extraction methods in the hemp industry.
Also primarily used in the cannabis space for recreational THC products. This method works by utilising very cold water to shock the trichomes (the part of the plant containing the most terpene and cannabinoid content) off of the plant material and then filtering them to separate from the water and rest of the biomass. This method is popular among consumers who are wary of the use of solvents but contains a high amount of lipid content and may require further processing.
CO2 extraction is a “solventless” process and uses a supercritical CO2 liquid. This is carbon dioxide compressed and heated to maintain its liquid property at high temperatures and pressures. Carbon dioxide is an inert gas which in itself is safer, although it does still require very high operating pressures which can be a hazard. Because CO2 is an inert gas, it does not dissolve the target cannabinoid and terpene compounds. Instead it strips them from the plant material using pressure and temperature. While this leads to high efficiency in terms of yield, the temperature and pressure can break down some of the terpene content, and will extract significantly more lipids from the material requiring much heavier post processing. This method offers slightly higher efficacy than hydrocarbon extraction regarding medicinal efficacy. However, it does not best alcohol extraction on this measure.
This is quickly becoming the most popular method for hemp extraction. This process allows for high throughput utilising a solvent (usually ethanol) that is Generally Recognised As Safe (GRAS). Extraction labs can work with alcohol at room temperature and regular pressure, thus maintaining a safe work environment at all times. The resulting extracts offer the most medicinal benefit of all other common extraction solvents in the industry. This is thanks to its selectivity for both polar and non polar constituents found in the plant material. Ergo, alcohol extraction is most effective at gathering as much of the spectrum of the plant contents versus other methods. We’ll talk more on Polarity later!
CBD Product Types
This product refers to concentrate manufactured using the CO2 Extraction method. It is an unrefined oil. It has a high lipid content, so this product should be further refined in order to smoke, vaporise, or formulate into finished edible or topical products. However, some CBD brands don’t always follow this practice. Due to the way CO2 extracts cannabinoids and terpenes, it can sometimes lead to a degraded flavor profile and diminished medicinal benefits. Usually, a lab will take this product and further refine it to a distillate or isolate product.
Broad Spectrum Distillate
Distilled oil can be made from almost any type of extract as it is simply a purification process. It removes the lipid content (i.e. fats) to create a clear and transparent appearance. In addition, the process results in the removal of most terpenes to give the distilled oil an odourless and tasteless property. It makes it perfect for formulating into products such as edibles, tinctures and topicals.
CBD Distillate typically contains 80-95% of active cannabinoids. This makes the product format very easy to dose and formulate as it is a much purer oil versus the starting material. Vape pens and cartridges heavily use distillate as it tends to be a clean base product to add flavouring to for a consistent experience every time.
‘Isolate’ simply refers to a single molecule extracted from the rest of the constituents found in the plant. A CBD isolate, for example, will commonly test around 99% CBD purity. Thanks to that level of purity, the industry considers it an API (Active Pharmaceutical Ingredient). Because CBD isolate is effectively THC free, CBD brands outside the US often like to use it to formulate their hemp CBD products. Unfortunately this also strips the CBD of most of its benefit.
As we learn more about the cannabis and hemp plants, we are discovering that a lot of the effect in our bodies is not specifically down to the CBD alone, but also the other hemp compounds that are with it. CBD acts as a guide to bind to its correct CB receptors more efficiently. So, when you take these other compounds out of the equation, the medicinal benefit can sometimes be lacklustre. So, if using CBD Isolate, it is important to formulate the rest of the product with constituents that will benefit from the presence of CBD, and not just focus on CBD as the only active.
Full Spectrum CBD Oil
There is a lot of confusion over what Full Spectrum CBD Oil is. Many companies state that their product is in fact a full spectrum product without truly understanding what they are saying. The spectrum of an extract simple refers to what is available in the starting plant material. To have a “full spectrum”, the extract must contain everything that was in the starting biomass (i.e. the hemp plant). This will have a significant impact on the efficacy of the manufactured product. After all, we believe it is this spectrum that carries most of the medicinal benefits.
Full Spectrum CBD Oil and Polarity
When we discuss this type of product, it is important to understand the extraction solvent used and its properties. One of the most important properties to focus on is Polarity. Polarity is an index from 0 to 1 that alludes to the shape of the molecule. 0 is very non polar, and 1 is very polar. The most important concept here is that like dissolves like. What that means is that polar solvents will dissolve (extract) polar compounds. Meanwhile, non polar solvents will dissolve non polar compounds. Think about water and oil separating in a salad dressing: the water is very polar, while the oil is very non polar. This may seem simple but it is one of the most vital concepts in creating a full spectrum CBD oil.
When analysing solvents by polarity the most common non polar solvents are hydrocarbon and CO2. The most common polar solvent is water. Each of these solvents will extract their like polar or non polar compounds. While they may pick up some of the constituents on the other end of the index, it is always a very small proportion.
This is the reason why alcohol is an ideal extraction solvent for producing a full spectrum CBD product. It has a polarity index just above 0.6, so ethanol has an affinity for both polar AND non polar compounds. It is now clear why it is so important to understand what the extraction process is for, regarding what the desired type of product is at the end of the process.
Shatter, Budder, Sauce, Sugar, Live-Resin
Usually all of these extracts refer to hydrocarbon extracted products. It is this extraction method that yields the highest quality material. Consumer typically smoke or vape these products and they are most commonly made from cannabis material high in THC. We’d find these products more commonly in the USA where many states have legalised THC. While there has been some momentum in processing hemp material into CBD extracts of this type, it is very rare. These products do not hold the same medicinal efficacy as other types of extracts but are still useful depending on the ailment in question.
Hash, Sift, Rosin, Full-melt
“Solventless” products like these use the water extraction process. So, they do not rely on a traditional solvent to extract the target compounds. The market for this type of solventless product is again mostly on the recreational THC side of the industry in the USA. These products are typically very high in lipid content and its users smoke or vaporise it. These products can also be high in plant material depending on the post extraction processing.
CBD Spec Sheets
Below we have summaries of the major extract types that go into the CBD products available on the market today. We guide customers to broad spectrum products as it excludes the THC but includes all the other valuable cannabinoids alongside the CBD.
Full Spectrum Oil (FSO)
CBD %: 55-70%
Includes: Terpenes, fatty acids, chlorophyll, lipids, full spectrum of cannabinoids, THC
Excludes: Plant Material
Full Spectrum Oil refers to a crude oil extracted with an alcohol that includes as many fractions of the plant spectrum as possible. This oil is usually dark, full of fats, and extremely aromatic. We understand it is this oil type that is the most medicinally beneficial to the consumer. However, it is also in the least appealing state in terms of look and odour.
Broad Spectrum Distillate
CBD %: 75-90%
Includes: High boiling point terpenes, full spectrum of cannabinoids
Excludes: Plant material, low boiling point terpenes, chlorophyll, THC
Optional: Fatty acids, lipids
Broad Spectrum Distillate refers to oil that has been distilled. This oil excludes a majority of terpenes and chlorophyll while maintaining the full range of cannabinoids available to that strain. Some labs remove the fats and lipids from the oil, but it depends on the desired potency and end product. This oil is a light yellow colour with minimal odour that crystallises readily.
CBD %: 99+%
Includes: CBD Only
Excludes: Plant material, all terpenes, lipids, fatty acids, chlorophyll, all other cannabinoids
This material comes in crystal form, is white and odourless. It excludes anything other than the CBD cannabinoid and from what we understand so far has the least amount of medical benefit of all the states of oil. CBD isolate is the easiest to dose in terms of consistency, however. Because of its ease to work into different formulations it is the most pharma-like product.