Cannabis Extraction Process

Pre-Processing Stage: Biomass or “Raw” Cannabis

Welcome to the preparation or pre-processing phase of the cannabis extraction journey! All extraction begins with the mature, female cannabis or hemp plant in its “raw” or natural state.
Cannabis flowers, or “buds,” are the dense flower clusters that form along the upper portion of the main stems and large branches in the mature, female cannabis plant. Cannabis produces most of its trichomes—tiny hair-like outgrowths that can look like crystals—on its flowers. And trichomes are the magic factories that produce desirable compounds like cannabinoids (THC, CBD, etc.) and terpenes. All extraction methods are based on the goal of separating trichomes from the plant material to concentrate the compounds that they contain.
Once the plant has been harvested, dried, and sorted, the buds are separated from the stems and stalks, and all excess leaves are trimmed (usually by hand). Finally, the flower is cured to allow any remaining moisture to equalize and flavors develop.
Some of the most common and popular end-products that consumers and wholesalers seek out are found in this initial “raw” stage:

• Flower (a.k.a. “Nugs” or “Buds”) is the most common and preferred form of cannabis consumption. Consumers typically process the flower by grinding it and packing it into a pipe or bong or rolling into a joint or blunt. It is also frequently sold as pre-rolled joints or “pre-rolls.”
• Trim is composed of the tiny leaves that are cut off (“trimmed”) from the flower before it’s cured. Many of these leaves are coated in trichomes, making trim a valuable byproduct. Trim does not typically include the large fan leaves, stalks, or stems removed earlier in the process.  In order to maximize value, trim is commonly utilized in place of flower in later stages of processing.

Although flower is the most prized part of the cannabis plant because of its trichome concentration, trim also contains a relatively high proportion of those cannabinoid-producing hairs. Because of this, trim shouldn’t be overlooked as a valuable source of cannabinoids and terpenes.

Stage 1. Primary Derivatives

Cannabis flower and trim can be super dense and irregular in size, making it difficult to efficiently pack into an extraction machine. This problem is often solved by milling, or grinding, the cannabis into smaller particles. After milling, the cannabis is ready for the first stage of extraction. Extraction can be performed using either solvent or non-solvent based technologies to produce the Primary Derivatives.
These derivatives include a wide variety of products*:

• Terpenes (a.k.a. “Terps“) are the compounds that give cannabis and its derivatives their distinctive aromas and contribute to their varied flavors. Different combinations of terpenes are widely considered to be a driving factor in the type of high that consumers experience. Terpenes are included in nearly all cannabis- and hemp-related end-products (flower, vapes, edibles, drops, dabbles, edibles, topicals, etc.) except for isolates.
• Crude Oil (a.k.a. “Crude“) is a dark, highly viscous substance similar in texture to very thick molasses. Although it is very cannabinoid-rich, containing the major (CBD and THC) and minor cannabinoids (CBN, CBG, etc.), it also still contains undesirable components such as plant particulates, solids, and waxes. Removing these components requires that crude oil be further refined. Crude oil is one of the major building blocks of the cannabis industry because most end-products start off as crude before being further refined and purified.
• Resin/Live Resin:
  • Resin is usually produced using a solvent-based extraction method. It is composed of the valuable oily compounds contained in trichomes including terpenes, flavonoids, and high concentrations of cannabinoids like THC. It can also contain some undesirable elements like waxes and chlorophyll. Resin is typically further processed into dabbable concentrates.
  • Live Resin is produced by taking freshly harvested cannabis and freezing it to a subcritical temperature prior to the extraction process. By skipping the pre-processing drying and curing phases the fragile but flavor-rich “live” terpenes are retained. Live resin is typically consumed in the form of vapes and dabbable concentrates.
• Rosin/Live Rosin:
  • Rosin is a solventless extract obtained through the mechanical use of pressure directly on the cannabis flower. The high pressure forcefully separates the trichomes from the plant matter and results in a sticky oil. Rosin is typically consumed as a dabbable or smokeable concentrate.
  • Live Rosin is made from buds that were freshly frozen immediately after harvesting. Live rosin is a strong and flavorful pure concentrate. Typically used as a dabbable or in a vape pen, live rosin can also be added to hash, kief, or flower and smoked like other combustible products.
• Hash is one of the oldest cannabis derivatives known to humankind. It is created by mechanically separating the trichomes from the plant in a number of ways. Some of the most common methods for making hash include hand rubbing (“hashish”); sifting the dry flower using a screen (“dry sift”); and using ice cold water extraction, and a series of mesh screens to break off and sift out the trichomes (“ice/water/bubble hash”).

*Due to the evolving nature of this industry many of the terms we use to describe cannabis and hemp products may be used somewhat interchangeably. Words to describe various derivatives have evolved as colloquial slang, and as yet, there is not an agreed-to industry standard for many of these terms.
Primary Derivatives: Extraction Methods
Extraction methods utilized in Stage 1 are either solvent based or non-solvent (mechanical separation) based.
The widespread use of solvents to extract concentrates has been popular for many years in the modern cannabis industry. A growing number of consumers, however, are now seeking non-solvent or “solvent-less” types of concentrates because they are perceived as being safer to consume. Whether that is true or not remains a contentious topic within the industry.
The most common and widely used solvent-based extraction methods include:

• Ethanol (Alcohol, a.k.a. Ethyl Alcohol) is a colorless volatile flammable liquid. It’s the intoxicating agent in liquor and is also used to dilute motor fuel. Ethanol is one of the most popular solvents for cannabis extraction, is relatively easy to learn, and allows for a fairly safe extraction process.
• CO₂ (Carbon Dioxide) is used to extract concentrates under high pressure and extremely low temperatures to isolate, preserve, and maintain the purity of the extracted oil. CO₂ extraction requires sophisticated equipment and significantly more training than ethanol extraction. When executed correctly the end-product is safe, potent, and free of chlorophyll.
• Hydrocarbons (Butane, Propane, Methane): Another popular method is the use of hydrocarbon injection. In this method, hydrocarbons are used as a solvent to extract cannabis and terpenes. This method typically offers faster extraction rates than CO₂ extraction, and hydrocarbon cannabis extraction equipment is usually less expensive to purchase. The process delivers a potent end-product suitable for dabbing.
• Edible Oils: Extra virgin olive oil, coconut oil, butter, and other edible oils can be used to extract the fat-soluble cannabinoids by gently heating decarboxylated cannabis flower directly in the edible oil. The resulting oil has a much lower potency than other extraction methods. It is seen by some as a more natural alternative to chemical based extraction methods. Cannabis-infused oils are perishable and should be stored in a cool, temperature-controlled, dark place.
• Combination of different extraction methods (e.g. injecting ethanol into CO₂ stream): depending on your desired end-product, methods may be combined to increase operational efficiencies and vary end-product outputs.

The most popular non-solvent (mechanical separation) methods include:

• Water and/or Ice Based separation (“cold water extraction”) is ideal for producing ice water hash a.k.a. bubble hash. This method works by mechanically separating out cannabinoid-rich trichomes from the biomass through the use of water and/or ice, and an agitational force. Ice water-based extracts such as bubble hash, shatter, or crumble are ideal for dabbing and are arguably considered to be some of the highest-quality forms of cannabis concentrates available.
• Other non-solvent mechanical processes include the use of:
  • A grinder or screen to produce kief, a cannabis extract similar in appearance to sugar that can then be pressed into hash via the use of a hash press.
  • A rosin press that uses heat and pressure to squeeze cannabis oil out of biomass

Some of the outputs from the first stage of extraction can be sold directly to consumers, while others are now ready to move along to further stages of refinement and concentration.
Stage 1 derivatives typically contain between 10-60% cannabinoids. Further refinement increases product potency, versatility (for use in various end-products like vape cartridges and edibles) and adds value to the final retail price.

Stage 2. Secondary Derivatives

The second stage of cannabis processing involves further refining the derivatives produced in Stage 1. Stage 2 processing increases output potency, eliminates undesirable compounds, and, again, adds value to the final end-product.
Secondary Derivatives and accompanying end-products produced at this stage of refinement include:

• Refined Oil is the result of winterization and polishing and is ideal for use in end-products that are enriched by a full spectrum extract such as vape cartridges, tinctures, edibles, topicals, capsules, and sublingual products.
• Dabbable Concentrates are typically smoked using glass dab rigs. There are two general categories of these types of concentrates:
  • Non-Crystallized: Shatter, Budder/Wax, Crumble, etc.
  • Crystallized: Sugar, Diamond, Sauce, etc.

Stage 2 Refinement Processes
Stage 2 refinement generally includes the following processes:

• Winterization removes the fats, waxes, lipids from crude oil. Achieved by mixing crude oil with ethanol and freezing the solution to allow undesirable compounds to solidify, the solution is then filtered to separate or winterize waxes, lipids, and fats. Removing the ethanol from the solution is the final step. The finished product is known as winterized oil and is used in full spectrum end-products such as vape pens, tinctures, topicals, capsules, and sublingual products.
• Particulate Filtration (a.k.a. “polishing“) removes suspended particulates/adsorbents, and also enables the most efficient use of your chosen solvent. The end result of filtration is a lighter-colored cannabinoid-saturated solution that is ready to go into the evaporator.
• Solvent Evaporation is the process by which the solvent used to extract cannabinoids is removed from crude oil via evaporation.
• Vacuum Oven Treatment (for hydrocarbon solvents only) is used to separate out hydrocarbon solvents from the initial extraction, as well as influence the texture of the final concentrate. This treatment uses heat and sometimes a vacuum pump or vacuum oven depending on the desired end-product.
• Crystallization is the process by which THCA and crystallized dabbable concentrates are extracted by inducing crystallization process to crude oil and resin/live resin, respectively to produce Sugar, Diamond, Sauce, etc.

The cannabis derivatives produced in Stage 2 refinement have a cannabinoid concentration of approximately 40-75%. The most common end-products of this stage include most dabbable concentrates such as shatter, wax, crumble, sugar, and sauce.

Stage 3: Tertiary Derivatives

The third stage of the cannabis refinement journey increases the cannabinoid potency of the extracts to 70-95%. The Tertiary Derivatives and accompanying end-products produced include:

• Distillates are typically used in the manufacturing of most cannabis- and hemp-related end-products: vape cartridges, edibles and beverages, tinctures, topicals, capsules, and sublingual products.
• Recombined Derivatives are combinations of derivatives such as:
  • Terpenes + Winterized/Polished Oil
  • Terpenes + Distillates to produce full or broad spectrum extracts typically used for vape pen cartridges.

Stage 3 Refinement Processes
This third stage of refinement utilizes a variety of processes:

• Decarboxylation After Extraction is used to convert acid forms of cannabinoids, like THCa and CBDa, to their more popular neutral forms, like THC and CBD. Cannabis produces cannabinoids in their acidic or “raw” forms and they must be decarboxylated in order to obtain their neutral or “active” forms. Decarboxylation is a chemical reaction that is achieved by heating cannabinoids to a temperature at which they release a carboxyl group (a carbon atom double-bonded to an oxygen atom), hence “de-carboxyl-ation.”
• Distillation uses a vacuum and controlled residence time (amount of time the solution is exposed to heat) to achieve molecular separation of target compounds from crude oil to produce a more purified and potent cannabinoid concentrate known as distillate. Distillate may still contain some non-target compounds, differentiating it from the further refined isolate.
• Remediation is the process of removing certain undesirable compounds from cannabis or hemp distillate. This process is frequently used to remove THC from hemp-derived CBD products to ensure they contain ≤0.3% THC as per federal mandate. Other undesirable compounds that can be removed during this process are microbial contaminants and molds.
• Recombination of Derivatives may include the addition of terpenes to winterized oil or distillate, depending on the desired end-product. Recombined derivatives are most commonly used to add value and effectiveness by creating full spectrum extracts.

Stage 3 distillates are used in most end-product applications and may also be further refined into crystallized isolates in the next stage of processing.