What Happens During Decarboxylation, And How To Get It Right
If you have ever eaten raw cannabis hoping to get high, chances are you had a disappointing experience. This is because marijuana needs to go through the process known as decarboxylation before it is active.
WHAT IS DECARBOXYLATION?
In layman’s terms, decarboxylation is the process of heating up cannabis to activate the THC, CBD and other cannabinoids within it. Without heat, these compounds are unable to pass through the blood brain barrier. This is why marijuana is smoked, vaporised or cooked before it enters the body – it is pretty much required if you want the effects of the active compounds.
Looking at it a bit deeper, decarboxylation is a chemical reaction where the COOH carboxyl group of atoms are removed from the cannabis, exiting in the form of H2O and CO2, (water and carbon dioxide). As cannabis grows, it goes through a process known as photosynthesis. During this process, CO2 is absorbed, where it then combines with free hydrogen within the plant to create carboxylic acid. This is known as carboxylation. The main carboxylic acids of interest are THCA and CBDA, the precursors to THC and CBD respectively. When cannabis is growing, it is THCA and CBDA that it contains, not THC or CBD. This is why raw cannabis does not get you high in anywhere near the same capacity as decarboxylated cannabis.
The process of decarboxylation can occur naturally to some degree with time and heat, often as a process of drying cannabis, or being stored too long. But this natural decarboxylation is nowhere near as efficient or potent as human intervention, i.e. smoking, vaporising or cooking. When this occurs, the CO2 is removed from the acids, turning them into the much sought after cannabinoids.
However, there is another function at play here as well. One that recreational THC enthusiast will be keen to avoid. At around 70% decarboxylation, THC starts degrading into CBN, and it happens at a faster rate than THCA is being converted into THC, causing a rapid and significant drop in THC content. It is also worth noting that at this point, unconverted THCA is turned into CBNA, and CBNA continues to be converted into CBN, causing CBN content to rise even faster. THCA can also turn into CBNA with time and air exposure, which is partly why marijuana can lose its potency with age or improper storing.
Don’t let this scare you though. CBN has its uses, especially for medical oriented users. CBN is associated with being a sleep aid, an antioxidant, and a measure against glaucoma, amongst other things.
DECARBOXYLATING YOUR CANNABIS
As mentioned above, at around 70% decarboxylation THC begins to degrade into CBN, so depending on what you want from your cannabis will define at what temperature you do it, and how long for. Firstly, if you vaporize or smoke your cannabis ,this is pretty much a moot point, as decarboxylation happens instantly, and the only concern (with vaporization) is hitting the right temperature so that you do not destroy the cannabinoids. Manually decarboxylating your cannabis is for those who want to cook with it, or make certain extracts and oils.
Generally speaking, you want to decarboxylate your cannabis at around 106-120 degrees Celsius for between 30 min to an hour. Many people will happily decarboxylate there cannabis at 118-120 degrees Celsius for an hour, and generally see this as the standard. However using such a high temperature for this amount of time could be inadvisable (see below). A note for purists: decarboxylating your cannabis above 100 degrees Celsius straight away can cause any leftover moisture to boil and cause cellular damage to your cannabis – degrading its integrity. To avoid this, you can start by heating your cannabis at around 96 degrees Celsius for 15-20 minutes. This should dry out any remaining moisture, making it safe to move onto higher temperatures. This is quite a trivial matter though, and most people would never notice the difference.
The below graph from the Journal of Chromatography can give you a good insight as to how temperature and time affect peak THC content during decarboxylation. Bear in mind this was in a very controlled lab setting, using a marijuana extract “on a glass surface in an open reactor” – but it should give you a rough guide. According to its findings, you may want to cut down the heating time to around 30 minutes if you are using higher temperatures.
There you go! Whilst not really necessary to know, having a better understanding of decarboxylation can help deepen your wider knowledge of cannabis, and how its chemistry affects us – especially if you plan to make edibles. Honing your timing and temperature skills could even give you a great deal more control over the potency! Remember people, knowledge is power.