Ethanol Extraction: The Best Method to Extract CBD Oil From Cannabis
CBD is short for cannabidiol, which is a trending ingredient in the natural products industry. It’s one of the many compounds found in the hemp.
CBD is short for cannabidiol, which is a trending ingredient in the natural products industry . It’s one of the many compounds found in the hemp plant and is gaining more and more popularity for the numerous medicinal uses it has had over the past few years.
Without the compound that gives you the “high” while using cannabis, tetrahydrocannabinol (THC), CBD oil comprises a wide range of health benefits, including anti-inflammatories, antioxidants, antipsychotics, anticonvulsants, etc.
However, consumers cannot gain these benefits simply by purchasing the cannabis plant. All beneficial compounds should be extracted by a certified manufacturer and transformed into oil extract, which can later be used as an ingredient in products like edibles, creams, oils, and so on.
CBD — Where It Stands In Today’s Market
People in the cannabis industry are always on the search for efficient techniques of CBD extraction. This hunt is inspired by the demand for innovative tools to stay in tune with growing needs, as well as to be ready for a market that is federally regulated, which many predict is soon arriving.
With more and more new players joining the already competitive market daily, the technology required to reap the utmost benefits of the cannabis plant is advancing like never before.
This needed innovation is constantly being pushed by industry-leading companies. Ethanol extraction has evolved into the safest, most efficient method for extracting CBD oil from hemp fibers.
What Exactly is Ethanol?
Ethanol, commonly known as grain alcohol or ethyl alcohol, is a volatile, colorless flammable liquid. It’s used to produce gasoline, paints, solvents, food additives, and beauty products. If you’ve ever consumed beer, spirits, or wine, you’ve probably had ethyl alcohol in your system.
Furthermore, ethanol is used to extract chemical compounds from cannabis.
It’s fermented from several different sources and refined. Corn is one of the most used feed stocks for ethanol production. As for other sources, there is wheat, sugar cane, barley, grain sorghum, and potatoes. Because ethanol is obtained from plant material, it is considered a renewable source of energy.
According to the FDA , ethanol (C2H6O) is rated a Class 3 solvent with relatively low toxic risks when applied in pharmaceutical manufacturing where the residual is under 5,000 ppm or 0.5%.
There are several different ways to extract CBD oil with the help of ethanol extraction. However, the general process includes heating the hemp plant material to obtain decarboxylation — a key step for efficient production of the main active components in cannabis — and then soaking the plant material in ethanol for a specific amount of time.
Once the time’s elapsed, the final solution is filtered in order to separate the liquids from the hemp plant matter. After that, the liquid is left inside an open dish to let the ethanol evaporate.
Since ethanol is a plant-based solvent, many experts believe ethanol cannabis extraction is the most efficient method for maintaining the chemical ratios which naturally exist in hemp. This is why manufacturers have been able to scale up their ethanol extraction technology for high-volume CBD businesses, while still keeping things simple.
Ethanol not only extracts water but also the oil-soluble compounds.
Chlorophyll is one of the many compounds that ethanol extracts so effectively. While it closely mirrors hemoglobin and offers similar, if not, more health benefits, chlorophyll can be somewhat grassy and bitter tasting. Keep in mind that this additional filtration of chlorophyll may reduce the CBD oil’s potency.
It’s also worth noting that eliminating the ethanol from the CBD oil is almost impossible without an added filter, further decreasing the potency and purity of the finished CBD oil.
Probably the most prominent benefit of ethanol cannabis extraction is the unique formation of esters , which are water-soluble, making them highly bioavailable — i.e., they are easily absorbed by the human body.
Therefore, by mixing the THCa or CBDa that transpires in raw cannabis with ethanol, you’ll end up with THC or CBD that’s easily absorbed by the body.
When it comes to CBD oil, bioavailability is extremely important. Oil-soluble compounds aren’t easy to digest and need to be broken down by the enzymes and acids in our body, reducing their purity and potency in the process.
Lastly, for the most health-conscious users out there, note that CBD oil extracted using ethanol is certified organic. That spells quality and reliability.
In today’s fast-growing cannabis market, extraction companies play a significant role in the production of top-tier CBD oil Products. There are a variety of different methods of CBD extraction, but each has its pros and cons. Speaking of which, here’s why ethanol extraction stands out among the rest:
- Easily scalable
- Extremely inexpensive equipment
- Less power-intensive than CO2
- The facility is less expensive as opposed to hydrocarbons
- Fast extractions – great for distillate products
If you made it this far, it’s safe to say that you can take a pretty good guess on why big-name manufacturers prefer using the ethanol extraction method. It produces CBD oil at a high potency and purity level, meaning high-quality CBD products end up at the stores for customers to benefit.
The Pros and Cons of Cannabis Ethanol Extraction
Freelance Science Writer
With the popularity of cannabis extracts burgeoning, there remains a huge market for products produced using solvents to extract desirable compounds from raw cannabis plants. While hydrocarbons and CO2 are preferred solvents for many producers, ethanol remains a solid option for small-scale and high-throughput producers alike.
Ethanol extraction has benefits and drawbacks over other types of extraction methods. But some of its pitfalls can be overcome by tweaking the type of ethanol extraction method used. For example, using cold ethanol will limit the levels of undesirable compounds that end up in solution. Opting for a warm ethanol process can provide a fuller plant profile, which may be considered beneficial for some products.
Why producers choose ethanol extraction
One of the main reasons ethanol extraction is favored by many producers is the low cost of this method. As Rubin Torf, co-founder of Scientia Labs, explained to Analytical Cannabis:
“Ethanol/alcohol extraction is best for high throughput because it generally has the lowest electrical costs per pound, and almost always a lower labor cost per pound of biomass processed. It is likely the cheapest equipment to scale, especially when safety concerns are taken into consideration.”
Ethanol extraction can help an extractor pull a broader range of compounds from the plant than when using other solvents. Although, this is sometimes considered a drawback.
As such, cost and extract profile are some of the major factors to bear in mind when considering different types of ethanol extraction.
Note that other alcohols may be used in cannabis extraction as an alternative to ethanol. For example, isopropanol is particularly popular among producers.
Types of ethanol extraction used in cannabis applications
Choosing to use ethanol in your extraction is just one step in the decision-making process. You also need to select an ethanol extraction method that works for you. There are several options available, mainly differing with respect to the temperature of the ethanol. Here’s a rundown of those types, including the advantages and disadvantages of each.
Room temperature and cold ethanol extraction
These two types of extraction follow the same basic steps. But, because of the difference in the temperature of the ethanol, they will yield different results. Both can be carried out using a relatively simple setup without requiring specialized equipment. Here are the main steps involved:
- The raw cannabis plant material is placed in a suitable vessel. It might be left loose or placed inside a bag (think of a very large teabag). The plant matter is completely covered with ethanol and left to soak. Soaking time will depend on the ethanol temperature and the desired profile of the product.
- During soaking, the ethanol will solubilize the cannabinoids (including THC and CBD) and possibly other compounds present in the plant, such as terpenes, pigments, and plant lipids. The specific compounds and their quantities will depend on the temperature of the ethanol, as well as various aspects of the plant matter, including strain, plant part, and condition of the raw material.
- After soaking, the plant material is separated from the ethanol solution. If a bag is used, this step might be as simple as removing the bag from the vessel. If loose plant matter is used, some type of filtration will be applied.
- The next stages will depend on a few factors including the temperature of the ethanol the desired final product. For example, a winterization step is often included to remove undesirable plant lipids from the extract. For some extracts, in particular those using cold ethanol, the solution will be acceptable as is.
- Now it’s time to remove the ethanol from the extract. This is often carried out using vacuum distillation in a rotary evaporator, but other methods include a falling film evaporator (often used in larger-scale production).
- Although most of the ethanol may be removed using those methods, there will usually still be an unacceptable level of ethanol in the extract. A vacuum oven is often used to purge the remaining alcohol, but a hotplate stirrer is another option.
By extracting at room temperature, an extractor can achieve a robust plant profile without the need for heating or cooling equipment. When Analytical Cannabis asked about the benefits of room temperature extraction, Torf revealed that lower equipment costs and a fuller product profile were major factors. He also explained:
“Most importantly, perhaps, is the overall extraction of CBD happens faster and more thoroughly at higher temperatures. We were achieving 90 percent plus CBD extraction from a range of biomass inputs.”
“I haven’t seen cold ethanol achieve these kinds of results from cold extraction, and it would seem to go counter to transport phenomena physics if cold extraction worked faster,” he added. “If we didn’t extract all CBD in the biomass, we would be leaving money on the table, so to speak.”
That said, an extractor will likely end up with some plant lipids in the room temperature extract, which, if undesirable, will need to be removed by a winterization step. This involves washing the extract with cold ethanol, allowing plant fats and waxes to precipitate out of the solution, and then filtering to remove them. Multiple winterization steps may be required to reach the desired final product.
When you opt for cold extraction, you have the task of keeping the mixture cold (usually below -30°C) for a long period of time while the plant soaks in the alcohol. This can be difficult if you want to work with larger quantities but are limited in terms of equipment. That said, one of the benefits is that cold ethanol won’t pull out plant lipids and pigments. This means you can avoid having to deal with a winterization step and may achieve a more optimal flavor profile.
Warm ethanol extraction
Warm or hot ethanol extraction typically requires special equipment. One popular method is the Soxhlet technique. The raw plant material is placed in a special piece of equipment called a Soxhlet extractor. Warm ethanol is passed over the material multiple times, and the solvent is recycled. Once the extraction is complete, additional steps such as winterization are carried out as needed and the ethanol is removed, usually via a rotary evaporator.
With warm ethanol extraction, an extractor can solubilize a border range of compounds from the plant matter. This means it can be a good choice if you want a full-spectrum extract. However, with high temperatures, you’ll solubilize pigments such as chlorophyll, which tends to have a bitter taste. You may also cause damage to sensitive compounds such as terpenes, further impacting the flavor of the extract. Removal of undesirable compounds is possible but can require multiple steps and a lengthy overall process.
Freelance Science Writer
Aimee is a freelance science writer with over a decade of experience as a development chemist. She has written for Analytical Cannabis since 2020.
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