The Best Methods for Extracting Hemp Terpenes

Blog, Extraction, Terpenes

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If it weren’t for hemp terpenes, any product derived from hemp would be largely undesirable due to a lack of flavor and aroma – let alone the lack of synergy between terps and cannabinoids. For those reasons, it is vital to make sure that terpene extraction is a primary consideration for hemp producers. In this article, we will discuss the best way to ensure that terpene extraction is thoroughly explained so that preservation and formulation of hemp terpenes is optimal.

terpenes in bottles

How Much are Hemp Terpenes Worth?

As stated previously, hemp terpenes have become incredibly valuable for creating any CBD product. But, what is the true value of hemp terpenes? If a producer is purchasing wholesale terpenes for product formulation, full spectrum natural hemp terpenes will cost roughly $20-30 per gram. Needless to say, these can be costly.

Because of this high cost, some producers may resort to synthetic terpenes running roughly $10-20 per gram. However, these terpenes are not highly sought after by consumers making it a lesser option for any producer.

So, in truth, terpenes are highly valuable for their use and for their overall price point, but to buy them wholesale is a far costlier choice. This is why proper terpene extraction is critical for any extraction company to master, and there are many factors that play into proper extraction of hemp terpenes.

One of those factors is in the decarboxylation process. Some extractors decide to decarb before extraction, some after extraction, and some don’t decarboxylate at all. So, what is the best choice for terpene extraction and preservation?

Decarboxylation Before or After Extraction for Hemp Terpenes?

While some may disagree, it is not required that you decarb your biomass before CO2 or ethanol extraction. Decarboxylation, or decarbing as it is commonly referred to, is a process that converts the acidic form of cannabinoid to a neutral form. Decarbing makes the cannabinoid more soluble in the solvent and therefore improves the time for extraction. CO2 is capable of extracting acidic forms of cannabinoids, however since the acidic form is much less soluble in CO2, it takes longer to extract from the biomass.

worker using decarb ovens

Decarbing hemp biomass before supercritical CO2 extraction is crucial to capturing terpenes

A small amount of ethanol such as 5% can be added to the CO2 stream to improve the time to extract CBDA oil or THCA.

If your plan is to produce distillate or CBD isolate, then you will always need to decarboxylate. Either you decarboxylate the oil after you extract it or you decarboxylate the input biomass.

One advantage of decarboxylating the biomass before extraction is that you will also be able to harvest terpenes from the biomass directly without a lot of processing. This preserves the essence of the plant so that it can be used for flavor and aroma in your formulation.This is a huge advantage for decarboxylating the biomass rather than decarboxylating the extracted THC or CBD oil after the extraction process.

What Happens to Hemp Terpene Profiles in CO2 Extraction vs Ethanol Extraction?


Terpenes are extracted by both ethanol and CO2. Here are the key differences in the terpene profiles of a CO2 extracted oil versus ethanol extraction.

  1. Ethanol will extract most of the terpenes that are in the biomass.
  2. Ethanol will extract most all of the biomass cellular material, fats, waxes, and contaminants.
  3. In order to get the ethanol out of the extract, a falling film evaporator is used.
  4. Terpenes that make up the aroma (low boiling point molecules) evaporate with the ethanol.
  5. Terpenes that remain in the oil typically break down easily but many terpene profiles are left in the remaining oil.
  6. This oil is not potent, is pitch black, and really does not smell good. Distillation is typically required as a secondary purification step..
cbd oil

What Method Is Best For Terpene Extraction?

Here are some things to keep in mind if you are an ethanol extractor:

  1. In ethanol extraction, removal of the ethanol is a process that requires a significant amount of heat over a long period of time. This heat exposure will degrade the terpenes significantly. Many of the terpenes during this process are co-distilled or are destroyed in the process. The oil from this process is typically dark black and does not taste very good. The aroma profile is also not very desirable due to the breakdown of the terpene profile. The use of a crude extract for the tincture it’s not desirable because it doesn’t taste very good, doesn’t smell very good, and it also may contain too much THC.
  2. Once the ethanol has been removed from the ethanol extract, the oil typically is introduced to a distillation process which removes the remaining terpenes. If your intent is to use distillate for your tincture, then you will have to find a way to add some terpenes to that tincture. The only resort is to purchase synthetic terpenes. you will also need to figure out how to reduce the amount of THC.
  3. One other thing that needs to be considered is that if you do not distill the ethanol extract, it is very likely that you will have a significant amount of chemical contaminants in your extract. This is especially true if you are using denatured ethanol for your extraction process.
ethanol on table from solvent recycling

Ethanol is a questionable extraction solvent for terpene extraction

In contrast, CO2 extraction is far superior in terms of terpene profile preservation:

  1. If you use the extraktlab process, you will start by harvesting the terpenes before CO2 extraction. This preserves many of the low boiling terpenes that are unique in significant to the strain hemp that you are extracting.
  2. You may also use subcritical CO2 in order to produce soupy mixtures of terpenes, cannabinoids and waxes. These terpy mixtures are typically very desirable for vapor pens but are not very desirable for the purpose of formulation. Because they have cannabinoids and waxes in them, using them as a way to introduce terpenes to a formulation is much more difficult to do and reproduce in practice.
  3. The CO2 extraction also avoids the issues related to chemical contaminants that come from the use of denatured ethanol.

In summary, call CO2 extraction and ethanol extraction can produce desirable extracts. However, CO2 extraction has an edge over ethanol extraction when it comes to the preservation of the hemp terpene profiles and the avoidance of risk related to chemical contaminants.

Can Ethanol Extractors Use CO2 for Stripping Hemp Terpenes?

Ethanol extraction typically destroys the terpenes when the ethanol is removed from the extract or is distilled from the winterized oil. Many ethanol extractors are seeking a way to preserve the terpene profile of the plant in the output oil. To this end people have tried techniques such as Steam distillation, CO2 stripping, and vacuum distillation.

Certainly, CO2 can be used to strip terpenes from hemp biomass prior to ethanol extraction. However, vacuum distillation is by far the most gentle and effective way to harvest the terpene profile prior to ethanol extraction.


Final Thoughts

No doubt, terpenes are as critical as the cannabinoids that accompany them, so terpene extraction is vital to a successful business. By following the extraktLAB method to terpene extraction, producers can rest assured that the terps they produce will be of the highest quality for wholesale or product formulation. And, while ethanol extraction can yield quality terps, it is our belief that supercritical CO2 extraction methods provide the best possible terpene yield – let alone the best possible CBD or THC yield as well.

If you are interested in stepping up your extraction to the highest quality CO2 systems available, it’s time to reach out. Give us a call at 651-600-0036 or schedule a free CBD Jam Session to speak with one of our knowledgeable representatives to identify your production bottlenecks and see how the extraktLAB solution fits into your business.

Cannabis terpenes displayed in snow

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Dr. Jon Thompson

Dr. Thompson is a separations scientist, entrepreneur, and inventor. As a scientist, he has a strong technical background and industry experience in analytical instrumentation, in-vitro diagnostics, biotech, mining, and homeland security markets.

During his career, Dr. Thompson has earned a strong track record of helping companies set up hemp and botanical extraction and processing facilities.

Dr. Thompson has assisted numerous companies to attain their goals in hemp manufacturing, as well as market development, strategic marketing, and worldwide business-to-business alliance formation (including international markets).

Dr. Thompson has a track record of writing winning licenses and has implemented hundreds of start-up operations in Canada, Europe and throughout the US for various clients. Dr. Thompson received a Bachelor of Science degree in Biochemistry, Chemistry and a Doctor of Chemistry degree from the University of Minnesota.