CBD Extraction Methods: What’s the Difference?
Most customers know to look for the hemp extract type and know there’s a huge difference between full-spectrum, CBD isolate, and broad-spectrum products. However, there’s another factor that is equally important to understand, but typically less advertised: the extraction method.
There are a number of extraction methods used in making hemp oils. Hemp extracts can be made in small batches at home or in massive quantities for retail, using everything from olive oil to dry ice. The most common industrial extraction methods used by large-scale hemp product companies are ethanol and CO2 extraction, so those are what we’ll focus on here.
What Does Extraction Mean?
The many compounds found in CBD tinctures, salves, vape oils, and so on don’t just come that way. The sought-after compounds in hemp are largely found within the fibers of hemp flowers, and you can’t tap stalks for a cannabinoid-rich oil like they’re syrup trees. To create the hemp products you see in the Apotheca store, all of the phytocannabinoids in hemp flowers are pulled from plant matter and suspended in a carrier liquid.
Extraction isn’t a concept unique to making hemp products: the same basic principle is at work when cooking a bone broth or vegetable stock. In cooking, sustained exposure to heat draws the nutrients and flavors from bones or vegetables and a pot of simmering water is the carrier liquid.
With broths, the water changes color from clear to a yellow or rich amber as nutrients are absorbed. The same process happens with hemp extracts, although the end result is typically a bit greener in color.
How Does Extraction Work?
The element that pulls nutrients from plant fibers depends on the extraction method used. Depending on the scale and equipment at play, extraction involves some combination of heat, pressure, and/or solvents.
A solvent is a liquid that dissolves a solute. The simplest example of a solvent and solute is water and salt. Water is the solvent, and when salt is stirred into warm water, it dissolves. There are many other solvents used in industrial processes and chemistry, including turpene, chloroform, acetone, and—most importantly for hemp extracts—ethanol.
Ethanol extraction has been employed in small and large scales throughout human history in making herbal tinctures. This method can be used to make full-spectrum hemp extracts, both in industrial settings and at home (though if you do that, you’ll want to be extremely careful for reasons we’ll explain in a moment).
Ethanol is a fairly simple compound, made up of two carbon atoms, six hydrogen, and one oxygen (C2H6O). It is naturally produced by fermenting sugar with yeast. Ethanol has a wide variety of uses outside of as a chemical solvent, including recreation (drinking alcohol), sterilization in medical settings, and as an alternative fuel source. It is a volatile chemical and is highly flammable, which is why any ethanol extraction requires extreme care and a controlled environment.
Ethanol extraction is an easy process on paper. Hemp flowers are mixed together with ethanol, strained, and then the resulting liquid is slowly heated until the ethanol cooks off. The actual extraction process can be conducted in warm or cool conditions, with more or less waxes and pigments extracted depending on the temperature.
The most important part of creating an ethanol-derived hemp extract is removing the solvent from the final product. Even the most efficient industrial processes require a half gallon or more of ethanol per pound of plant matter. Before extract can go through additional manufacturing processes, large-scale operations must put their extract through a series of solvent recovery and purification processes. Depending on the amount of product made and the desired purity level, this entire process can take days or weeks to produce one batch.
CO2 (carbon dioxide) extraction is a much more elaborate process that requires massive, expensive machinery. Unlike ethanol extraction, there is no home CO2 extraction kit. Carbon dioxide extraction relies on heat and pressure to pull phytonutrients from plants. CO2 is a “tunable” solvent, meaning the level of heat and pressure used can be adjusted to create different end products.
Most of the time, hemp extracts are created using supercritical CO2. “Supercritical” refers to a state where carbon dioxide takes on properties of both a liquid and gas—it can permeate plant matter like a gas, but still carry phytonutrients like a liquid. This happens when CO2 is held above its critical temperature (87.98ºF) and critical pressure (1,071 psi) points.
In the supercritical extraction process, CO2 goes through one chamber where CO2 gas is subjected to temperature and pressure changes. It is then pushed through a second chamber filled with hemp plant matter. In the supercritical state, CO2 can pass through hemp plant material and extract a wide variety of nutrients in a quick, efficient, and clean manner.
Conversely, we have subcritical CO2 extraction. This process is far less common since it takes much longer and produces a lower yield per batch. Subcritical extraction happens at low pressure and low temperatures, which means that unlike supercritical extraction, it doesn’t damage terpenes.
The Pros and Cons of Ethanol Extraction
Ethanol extraction is favored by many because it delivers a true full-spectrum hemp extract, with minimal damage to terpenes, flavonoids, cannabinoids, and other phytonutrients. Full-spectrum extracts are favored by many customers due to the entourage effect, which shows that cannabinoids are more effective when taken together, even when some compounds are only found in trace amounts. Ethanol extraction is the best method for creating a true full-spectrum hemp product.
Ethanol extraction’s cons come in that ethanol is by nature a much more volatile compound than CO2, and also has its own unique taste and odor. Depending on the quality of extraction process, ethanol can sometimes still be found in the resulting hemp extract product. Ethanol extraction is also a much lengthier process than CO2 extraction due to the fact that ethanol must be slowly dissolved. The extra steps required to produce a clean ethanol extract product are typically passed on to the consumer in the form of higher prices.
The Pros and Cons of CO2 Extraction
CO2 extraction’s greatest benefit is that it can produce extracts tailored to certain needs. By adjusting the temperature and pressure levels, manufacturers can create a THC-free hemp extract or 99% pure CBD isolate. The adjustments needed to refine an extract can be made relatively simply by the sophisticated machinery used in CO2 extraction.
Hemp products made with CO2 extraction are typically made quicker than ethanol extraction products, allowing manufacturers to put out a larger volume of products faster. CO2 is also considered a clean solvent, leaving behind less contaminants and therefore requiring less refining before they can be packaged and sold. These advantages typically result in more affordable products for consumers.
The disadvantage of CO2 extraction is that it by nature destroys certain compounds. If you’re looking for a full terpene and flavonoid profile, CO2 hemp extracts are not for you.
As mentioned earlier, CO2 extraction requires incredibly expensive machines. This creates a barrier to entry for companies looking to get into the hemp business. Expensive, large machines, the facility to house them, and the staff to run them aren’t typically within a small business’s budget. This means a number of smaller companies need to outsource their hemp extract from a third party. If you’re looking for a fully vertically integrated hemp business, you will need to do quite a bit of research—especially if they’re using CO2 extract.
Finding the Right Hemp Product for You
While it may be a bit of a letdown for the end of this article, there is no “right” method of hemp extraction. Each has its own advantages and disadvantages, and each customer will have to research the available products and weigh their priorities. If full-spectrum hemp is your priority, you’ll want to look for ethanol products. If you’re on a tight budget or want a CBD isolate product, CO2 is the way to go.
At Apotheca, we offer a wide variety of tinctures, salves, vape oils, and more. Our products are selected by our staff of hemp experts and are always third-party tested for contaminants and cannabinoid content. For a diverse selection of ethanol and CO2 extraction hemp products, visit our store.