Why You Should Decarboxylate Before Extracting

The most abundant cannabinoid in a typical cannabis plant is THCa. This is the acidic precursor to THC, which is non-psychoactive. To make it psychoactive, the molecule may be heated to remove a carboxyl functional group from its structure. This process is called decarboxylation and occurs when the plant is smoked. This is why eating an untampered plant will not give one a psychoactive effect, but smoking it will. This process also occurs in CBD. CBDa loses its functional group and becomes CBD, which has different chemical and medicinal properties. Orally-ingested CBD oil must first be decarboxylated before it can function as an analgesic.


The process of decarboxylation can be done in an extraction lab by heating the material at a certain temperature for a certain amount of time. This can be done in a forced air or vacuum oven with flower or on a hotplate with oil. It is still common to perform decarboxylation on the oil after extraction, however it is beneficial to perform this process on the flower beforehand for a variety of reasons:


1. The process removes moisture content, which can drastically affect yields. 


Heating the material removes water from the plant. Water makes extractions slower and less efficient by interacting with the solvent. Hydrocarbons and supercritical CO2 are fat-soluble as opposed to water-soluble. This means that the flow inside the extraction column is affected when water is present. In addition, water may form ice blockages in the extraction column, sealing off and preventing cannabinoids from being extracted. Although moist material is frequently used to lighten the final product, the spent material that is thrown away is still full of cannabinoids.


2. Acidic, precursor cannabinoids are less soluble. 


THCa and CBDa are more polar. This means that they are less soluble in lipophilic solvents, like hydrocarbons and supercritical CO2 than their non-acidic counterparts (THC and CBD). Therefore, going through the process of decarboxylation beforehand will make your solvent more effective at capturing cannabinoids. This is another reason why decarboxylation beforehand can reduce runtimes and increase yields.


3. It’s easier to decarboxylate flower than an oil. 


Decarboxylation requires controlling high temperatures for long periods of time. Heating the material for too long at too high of a temperature can lead to a degradation of total cannabinoids. When done too short at too low of a temperature, precursor cannabinoids will not decarboxylate. The correct time and temperature during decarboxylation are important. An entire batch of oil will tend to stay at certain temperatures during phase changes. This makes it difficult to get the oil to the required temperature for decarboxylation to occur and control that temperature over long periods of time. An oil with more solvent or terpenes will take a longer amount of time to reach a certain temperature. Decarboxylating the flower beforehand makes the process more consistent and takes a less amount of time.


If your goal is to extract the most cannabinoids from the plant, you should always decarboxylate beforehand. Even when creating smokable products, it is beneficial from a production standpoint. The process preps the plant for optimum extraction, dramatically speeds up runtimes, and creates a more consistent product.