Whole-Plant Extractions, Distillations, and Isolation

What do these terms mean and what’s the difference among them?

by

Timothy Byars

President, Chief Education Officer

Radicle Health

Extraction is a simple process that has been used for centuries to collect desirable plant

compounds and leave behind unusable plant material. For example, making espresso is an extraction process. Water is filtered through ground coffee beans and strips the beans of their oils. The oils contain the caffeine, flavor, and aroma. The result is a filtered,

concentrated solution.

In the cannabis industry, sophisticated technologies and techniques are being brought to bear on very old extraction processes to better enable manufacturers to separate out specific, desired plant compounds. Critics might suggest that these processes compromise the integrity or quality of the final products. Advocates prefer the control these processes provide to manufacturers to improve user experience and product quality.

First, let’s address the term whole-plant. Many manufactures state that their products are whole-plant or full-spectrum. At some level, these are marketing terms. Whole-plant products are often contrasted with isolates (products processed to the point where they contain only a single ingredient). Whole-plant intends to convey the idea that the products contain some combination of beneficial compounds that occur naturally in cannabis, and that this combination of compounds produces a synergy of effects greater than the sum of its parts (this is referred to as the entourage effect). The goal of a whole-plant process is to create products with a diversity of compounds, and these ingredients impact the flavor, aroma, experience, and therapeutic effects attributed to individual chemovars and to any products subsequently made from those chemovars.

That said, the differences between whole-plant derived products and products that have undergone more rigorous processing are more appropriately defined on a spectrum. Nearly all cannabis products are processed in some manner, meaning that they are subject to some refinement (even cannabis flowers are dried, trimmed, and cured). The type of refinement required by a cannabis product is dictated by the end product itself. For example, vape pen cartridges have different extraction requirements than do edibles—often these requirements are based on aesthetic (for example, the color of a product), the consistency, or the taste.[1]

At one end of the spectrum exist products that undergo very little processing. Rosin, for example, simply requires heat and pressure. This process requires no solvents or other chemicals, and can be made in mere minutes. Crude extracts are the result of a basic extraction, often with ethanol or CO2. FECO (fully extracted cannabis oil), which is a black, tar-like and viscous cannabis product is an example of a crude extract. Among manufactured cannabis products, rosin and crude extracts contain the widest array of cannabis plant compounds, including cannabinoids, terpenes, flavonoids, chlorophylls, and waxes. At the opposite end of the spectrum are isolates—processed (or purified, depending on your perspective) to the extent that only a single ingredient exists in the product.

Most products lie somewhere between these two poles. Companies will state that their products are whole-plant or full-spectrum even when those products have undergone further types of process refinement beyond crude extract.

Distillation

To further refine an extract (and to increase purity and potency) chemists can separate and capture individual chemical compounds—each terpene and each cannabinoid—because many of the boiling points (or vaporization points) of these compounds are different. This process is called fractional distillation.

Distillation uses heat to vaporize cannabinoids and terpenes. The distillation process begins with a cannabis extract, typically with a potency ranging from 40-70%. Heat is applied to the extract at a specific temperature to evaporate a desired ingredient (remember—the ingredients vaporize at distinct temperatures). The desired ingredient is isolated, captured, and cooled until it condenses back into a liquid, creating a new concentrate that is mostly clean of solvents, additives, and impurities. The final product contains a pure and very potent cannabis oil that can range from 90-99% of the targeted ingredients. Companies often run the distillation process multiple times, each time capturing a different targeted ingredient to add to the final product. Cannabis distillate oils are tasteless and odorless can be infused into a variety of different products. Or, some companies finish the oils by adding terpenes to mimic the attributes noted in specific chemovars and terpene profiles.

There are critics of fractional distillation. Some critics find fault with what they perceive as engineered cannabis products, where the plant is deconstructed and reconstructed using only targeted ingredients. And, distillates require more processing, which raises the costs (of course, consumers can use less of a distillate product than products with lower potencies to achieve the same effects).

Isolation

Isolate products are the purest form of single ingredient cannabis products available. While products made from fractional distillation often include multiple cannabinoids and terpenes, an isolate contains a single molecule only. Isolates are, essentially, refined distillates.

Typically, isolates are crystalline solids or powder mixtures that contain approximately 99% of a single cannabinoid (for example, THC, CBD, or CBG). Isolates (and distillates) are decarboxylated (meaning that all the cannabinoids are active) so users can consume these products via inhalation, infuse them into food or beverages, or ingest them as is.

The key difference between extraction and isolation is that extraction is a technique in which we can separate a compound from a mixture, whereas isolation is a technique we use to purify one extracted compound.

To help us understand the differences among extraction processes, filtering, and final products, Luce Farms—an organic and sustainable hemp farm in Vermont—makes the following analogy:[2]

Consider raw milk—it comes directly from a cow or a goat and remains in its natural form (it has not been pasteurized or changed in any way). Raw milk would be the equivalent to a crude, whole plant cannabis extract. If the milk were pasteurized, that process strips the milk of some bacteria and enzymes. And, the milk can be homogenized and fats can be removed from the milk. At this stage, the milk would be similar to a fractionally distilled cannabis product. Further processing can produce powdered milk, where the milk is refined to such an extent that no longer requires refrigeration. This stage of processing is similar to creating a cannabis isolate.

Does rigorous processing compromise product quality? It depends on whom you ask. Advocates of whole-plant cannabis products will emphasize the benefits of the entourage effect, where multiple cannabinoids, terpenes, flavonoids, and other material in the plant work together to create a synergy of benefits. Advocates of fractional distillation might emphasize the benefits of having more control over which cannabinoids and terpenes are in a product and eliminating by-products that detract from taste and user experience (such as plant chlorophyll, which has a harsh and grassy flavor; and waxes, which are sticky and require additional solvents to break down). Advocates of isolates might emphasize the purity of products. For example, a user might want to use a single cannabinoid (such as CBD) or might prefer the wide range of products that are manufactured with isolates and available in cannabis markets.

When cannabis plants are heavily processed, however, it means that solvents or other chemicals were likely used during manufacturing to create a more refined end-product. How well those solvents were removed from the final product will impact product safety. If you're unsure about the ingredients in your cannabis products, ask to see a certificate of analysis.

You can find more information about extraction processes in the Radicle Health Cannabis Foundations course, here:

https://radiclehealth.thinkific.com/collections

Join the Radicle Community! The Radicle Community is comprised of advocates, educators, healthcare professionals, and cannabis stakeholders and provides support, information, and resources to its members. Members of the Radicle Community can attend Radicle Community webinars for free and have access to exclusive content:

https://www.radiclehealthcare.com/radicle-community

What's your experience with extraction techniques? Leave a comment below!

References

[1] https://www.cannabisbusinesstimes.com/article/a-crude-awakening/

[2] https://lucefarmvt.com/about-us/