Producing CBD oil is a complicated process that requires cooperation between several different specialized fields. First, hemp farmers need to grow high-quality products that adhere to federal and state laws. Hemp is considered legal if it contains less than 0.3% THC. Then, a team of extractors needs to process the plant matter and refine it into CBD extract. That might sound like a simple two-step process, but it’s not. These two components are each complicated procedures by themselves, and it can take months of hard work to turn a hemp seed into a bottle of CBD oil. 

Growing the Plants

Luckily for CBD companies, hemp is an extremely easy plant to cultivate. It can grow anywhere except dry desert climates and high alpine mountains. Where it really thrives, though, in areas with mild winters and soil loaded with organic material to feed it.

Hemp’s growing cycle lasts between 110 and 120 days, and if farmers are growing outdoors, they may only have one growing season per year. Once the plants are mature, the farmers must harvest their crop and store it in a low-moisture area to dry. After the plant matter is dry, the farmers ship it to the extractors.

A Background on Supercritical CO2 Extraction

Although we didn’t think of the term until the 20th century, humans have extracted essential oils for aromatherapy since the days of ancient China. Today, we use those same techniques to produce CBD oil. Whenever a company tries to create a CBD extract using CO2, they have one main goal. They want to remove as much plant matter from their final product as possible while ensuring that important compounds, like cannabinoids, remain in the extract. This technique isn’t unique to CBD extraction. In fact, every time that someone makes a cup of coffee, they’re using CO2 to extract the caffeine from beans.

Although there isn’t much in the way of standardization in the CBD industry, supercritical CO2 extraction is about as close as it gets. It’s the “industry standard” technique for extracting phytocannabinoids like CBD and CBG as well as terpenes like limonene, myrcene, and linalool. 

Supercritical CO2 extraction is the technique we use at Root to Flower to produce our CBD oil.

The technique has a few advantages over other types of CBD extraction. First, CO2 is a much more stable chemical than other common solvents like butane or hexane. These two solvents are extremely unstable compared to CO2, and can explode if they’re not kept under the correct conditions.

CO2 is also much better at extracting terpenes from hemp plants than other solvents are. Additionally, CO2 is a much cleaner solvent than many other widely-available compounds. Therefore, any CBD oil made using this process is purer than oil from other solvents and requires less post-production cleaning. In addition to being an extremely stable chemical, CO2 has a variety of different properties at different temperatures and atmospheric pressures. Because of this, extractors can control exactly what compounds go into their extract by managing these variables. 

Supercritical CO2 Explained

Supercritical CO2 is a form of carbon dioxide that forms under high temperature and high pressure. While CO2 usually exists as a gas in nature, once it’s reduced to -69 degrees Fahrenheit and 50 pounds per square inch, CO2 will become supercritical and turn into a liquid.

Using supercritical CO2, extractors can isolate specific compounds, like cannabinoids, and either add or remove them from an extract as they see fit. When you consider that there are more than 100 cannabinoids in hemp, the ability to pick and choose what goes into an extract becomes invaluable. 

Additionally, extractors can use supercritical CO2 extraction to remove unwanted adulterants from their CBD oil like bacteria, bugs, or fungus. Finally, CO2 doesn’t have a particularly strong taste on its own. As a result, CBD oils produced using supercritical CO2 extraction allow users to experience the taste of the oil itself.

Supercritical CO2 Extraction Step-By-Step

  1. The extractors put plant material into a chamber in the extraction rig.
  2. The extractor pumps CO2 gas into a chamber. As they pump in more gas into the machine, pressure increases.
  3. Extractors reduce temperature to -69 degrees.
  4. CO2 becomes supercritical and exhibits traits of both a liquid and a gas.
  5. Supercritical CO2 pumps through the chamber containing hemp plant material. As it does, it dissolves parts of the plant into it.
  6. Once the CO2 passes through the plant matter completely, extractors purge it from the system.
  7. After this whole process is complete, the end product is CBD oil. Extractors take the CBD oil and mix it with a carrier oil, like MCT oil.


Other Kinds of CBD Extraction

While supercritical CO2 is one of the most popular ways to extract hemp oil from plant matter, it’s not the only one. There are several other extraction methods CBD producers use. For example, one popular way to make CBD extracts without using CO2 is by utilizing steam distillation. However, this is generally seen as inefficient and requires significantly more plant matter to produce the same amount of CBD oil as CO2 extraction. 

There are also other solvents, like butane, ethanol, and hexane that extractors can use to pull CBD oil out of plant matter. These are less stable than CO2 though, and require thorough cleaning  and purging on the solvent to achieve the same quality of product.

The Bottom Line

Making quality CBD oil isn’t an easy process. There’s an entire supply chain involved with getting sourcing plants, growing them, harvesting them, and getting plant matter to an extractor. And that’s all before the extraction even happens. Getting every bottle of CBD oil to a store takes months of planning. Keep all that in mind the next time you’re picking up a tincture of CBD oil at the store or online. If you want to check out some CBD oil that Root to Flower has put together recently, check out our online shop at