Despite its growing popularity, much of the general public is still uneducated when it comes to marijuana. For example, few understand the chemical reasons why cannabis has to be heated – or decarboxylated – prior to consumption.
If you were to consume a bag of ‘raw’ weed, the effects would be very minimal. Decarboxylation converts the major phytocannabinoids in cannabis (namely THC and CBD) into “active” molecular forms that are able to influence neurotransmitters in our body. In fact, without decarboxylation, marijuana would possess few – if any – of its medical and recreational properties.
Decarboxylation: A Requisite Chemical Reaction for Cannabis Edibles, Oils, and More
When you heat cannabis, you help activate the active compounds that lie within it. For example, if you decide to make edibles with marijuana, the flowers need to be decarboxylated first. If you fail to decarb your weed, you’re doing little more than adding raw plant matter. As nutritious as raw cannabis is, it does little in terms of producing therapeutic benefit.
Raw Cannabis vs. Decarboxylated Cannabis
‘Raw’ cannabis is plant matter that has not been dried or cured. Once cured, a small amount of decarboxylation occurs. The rest takes place when the plant material is heated – or combusted – to temperatures above 200 degrees Fahrenheit.
However, marijuana still has beneficial uses in its raw, uncured form. Prior to curing and decarboxylation, THC and CBD – the two most active compounds in cannabis – exist as acids (THC-A and CBD-A). These acids possess anti-inflammatory effects, similar to the types of vitamins and minerals that are found in other plant-based foods.
DID YOU KNOW? Eating raw cannabis has many nutritional health benefits?
If you consume raw weed, use either the fan leaves or flowers that have been freshly-picked. Raw marijuana can be stored in your refrigerator just as long as other greens like kale or spinach. It is important to monitor your raw cannabis, however, because it is prone to wilting and mold. This is particularly true for densely-packed flowers that contain a high moisture content.
If left undisturbed, the active compounds in cannabis will decarboxylate over time. However, total decarboxylation of THC-A and CBD-A in raw plant material would take years. When exposed to heat, the compounds decarboxylate instantaneously.
What is Decarboxylation?
Even though raw (carboxylated) cannabis possesses nutritional benefits, it is entirely non-psychoactive. In other words, it will not produce a high. In order to get the full effects of marijuana, it has to be heated – or decarboxylated.
As we mentioned above, the process of drying and curing can release a small amount of psychoactive compounds. However, this release pales in comparison to the amount of cannabinoids that are released during decarboxylation.
The actual term ‘decarboxylation’ refers to the chemical reaction that removes a carboxyl (COOH) group from THC-A and CBD-A. Carbon dioxide is released as a by-product of this combustion reaction. To decarboxylate marijuana, all you have to do is apply heat. But how much heat is necessary? Or in other words, at what temperature does marijuana decarboxylate?
We will answer this question later in the article. First, let’s take a look at some of the other advantages of decarboxylation — aside from the fact that it produces chemically-active forms of phytocannabinoids.
Advantages of Decarboxylation
One of the most common mistakes people make when making edibles from marijuana is failing to decarb their weed. Unless you’ll be baking your edibles (pot brownies, cookies, etc) prior to consumption, it is necessary to use an oven to heat the plant material and release the “activated” THC and CBD.
Incidentally, when you decarb weed for edibles you also reduce the risk of botulism. When you don’t go through the process correctly, botulism bacteria can easily grow in things like cannabutter and canna-oil.
Of course, every time you light up a joint or vaporize your weed you are automatically decarbing it. You convert one compound into another, and transform the plant material from nutritional to medicinal. In the absence of its carboxyl group, tetrahydrocannabinol (THC) can bind to cell receptors in our body tissues and central nervous system. But what about cannabidiol – does CBD need to be decarboxylated?
Why You Need to Decarboxylate CBD Strains
You could be forgiven for thinking that CBD decarboxylation is unnecessary. After all, why would you need to decarb a strain that’s already non-psychoactive?
In reality, the same decarboxylation rules apply to CBD as they do to THC. Because raw cannabis contains the acid form of CBD (CBD-A), CBD strains must be heated in order to “release” their active therapeutic properties. Like THC-A, CBD-A has its own health properties. In fact, it’s believed that if you consume CBD-A, your body will metabolize it and break it down into CBD on its own.
Decarboxylation of CBD increases its bioavailability, making more of it available to the body’s cells.
However, cells need to work extra hard to break down CBD’s carboxyl component. Moreover, much of the active compound will be lost as heat during the exothermic reaction. In other words, having your body decarb CBD on its own would be extremely inefficient.
Exposing the plant material to sufficient heat decarboxylates CBD instantaneously, as described above. Products like CBD oils or CBD gummies, however, have already been decarboxylated. This is why you can consume them in their natural state, without having to heat them.
How to Decarboxylate Weed
Aside from smoking or vaping, there are a multitude of ways to decarboxylate weed and gain its therapeutic and recreational effects. We’re going to show you the most basic one. You’ll need the following equipment:
- An oven
- A baking sheet
- Parchment paper
- Cannabis flower (trim, nugs, kief, etc.)
If you elect to use nugs, grind them coarsely before following these steps. In the following example, we used 40 grams of flower to produce a coconut canna-oil.
Step 1: Preheat the oven. Set the oven to 235 degrees Fahrenheit (120 degrees Celsius). Place the parchment paper on the baking sheet, and spread your marijuana flower across it. Make sure to break up larger pieces with your hands if necessary.
Step 2: Bake for approximately 40 minutes. This should be a sufficient amount of time for well-dried weed, but if you’re using fresher marijuana with more moisture, it could take up to 90 minutes. Some users invest in a hygrometer to check the level of moisture in their herb. It is easy to use; place the weed in a closed container with the hygrometer. After the weed is dry enough, leave it to completely cool.
Step 3: Remove and let cool. After 30 minutes, remove the baking sheet from the oven and let it cool down. The decarboxylation process is now complete, and the majority of THC-A and CBD-A should be converted into THC and CBD.
Decarboxylation Temperature for THC and CBD
If you ask twenty different cannabis users what temperature they decarb their weed at, don’t be surprised to get twenty different answers. What we can tell you is that the lower the decarboxylation temperature, the longer the chemical process takes. In fact, few people realize that if decarboxylation temperatures are too high for too long of a time, the active ingredients in the herb can be ruined.
There is dispute over the exact decarboxylation temperature of CBD. According to studies, however, it appears to be approximately 230 degrees Fahrenheit (110 degrees Celsius). As for the timeframe, neither THC nor CBD will decarboxylate instantaneously at their precise “decarb” temperatures. A longer period of time – typically between 40 and 60 minutes – will be required in order for the COOH group to break down into water and carbon dioxide.
Also, be advised that the boiling points of cannabinoids, terpenes, and flavonoids are much different than their decarboxylation points. Boiling points for these compounds have been much more thoroughly studied than decarb temperatures:
- CBC: 428 degrees Fahrenheit/220 degrees Celsius
- THC: 314.6 degrees Fahrenheit/157 degrees Celsius
- CBN: 365 degrees Fahrenheit/185 degrees Celsius
- THCV: 428 degrees Fahrenheit/220 degrees Celsius
- Myrcene: 330 – 334 degrees Fahrenheit/165 – 168 degrees Celsius
- Limonene: 350.6 degrees Fahrenheit/177 degrees Celsius
- Linalool: 388.4 degrees Fahrenheit/198 degrees Celsius
- a-pinene: 312.8 degrees Fahrenheit/156 degrees Celsius
Flavonoids and Phytosterols
- Beta-Sitosterol: 273.2 degrees Fahrenheit/134 degrees Celsius
- Cannflavin A: 359.6 degrees Fahrenheit/182 degrees Celsius
- Apigenin: 352.4 degrees Fahrenheit/178 degrees Celsius
- Quercetin: 482 degrees Fahrenheit/250 degrees Celsius
It is advisable to keep your decarboxylation temperatures on the low side to preserve terpenes. There are also compounds that are volatile and evaporate at higher temperatures. The result is foul odors and an unpleasant taste. If you plan to preserve your terpenes, try and keep the temperature in the 200-300 degree Fahrenheit range.
Now that we know the key to faster decarboxylation is greater heat (within reason), it should be a straightforward process, right? Unfortunately, it isn’t quite as easy as that. The existence of another mechanism means we have to control decarboxylation temperatures very carefully.
When we heat weed and turn THC-A into THC, or CBD-A into CBD, we also convert THC to CBN at a quicker rate. Once we reach 70% decarb, THC gets converted into CBN at a faster rate than the conversion of THCA into THC. In other words, when we go beyond 70% decarboxylation, THC levels apparently start to fall off quickly – as you can see in the following chart.
As helpful as graphs are, there is always an issue with the interpretation of data. For instance, the graph above relates to marijuana extract data. It transpires that the temperatures used for kief, bud or trim would be different. Also, the graph was created in 1990, and involved decarb of a hexane extract in an open container on a hot plate. With modern equipment, it is possible to reach 100% decarb without damaging your THC content.
The mystery of decarbing temperature was somewhat solved thanks to the efforts of Marijuana Growers HQ. In 2012, they tested cannabis trim and kief at 240 degrees for 30 and 60 minutes. The results are outlined in the table above.
A stable temperature of 240 degrees was chosen because, during their research, it was discovered that the vapor point of all major terpenes, flavonoids, and cannabinoids was right around 246.2 degrees. As consumer-grade ovens are not that reliable when reading temperatures, they played it safe by staying a few degrees below.
According to the results, 30 minutes was not long enough to completely decarb either the trim or the kief. The latter had reached 90%, but the former only managed 60%. Both were very close to 100% once the hour mark had been reached.
Decarboxylation Methods Investigated
It is assumed that the oven is the best way to decarb, but is this really the case? Bear in mind that most ovens will fluctuate by 10 degrees in either direction. When using the oven in the 250-400-degree range in particular, if the heat is 10-15 degrees more than what you’ve set, the result could mean the loss of important compounds.
DID YOU KNOW? You could lose up to 33% of your THC via oven decarboxylation.
The crockpot/water bath method is a popular one because water boils at a very consistent temperature of 212 degrees (depending on altitude). The problem with this method is that, while the max temp you use here will preserve all compounds, it is impossible to achieve full decarb.
This is because decarboxylation is not a linear process, as the last part of the THC-A to THC conversion process takes longer. When you use boiling water, the weed is exposed to heat for too long, and this causes degradation.
There is a product on the market called “Nova,” which claims to decarb cannabinoids with 100% efficiency. It provides lab tests to back up this claim, so it may be worth checking out if you’re dedicated to keeping the strength of your weed intact.
The other issue with decarb charts, graphs or anything else showing this kind of information is a lack of knowledge of the precise starting point of the decarb process. In other words, the times and temperature figures shown are always an average. Remember, you can’t place dry material in an oven at a specific temperature and expect it to remain at that exact level for the duration of the decarbing process.
How to Decarboxylate Kief
Kief is the name given to the crystallized structures that stick to the surface of pure weed. In other words, it is essentially cannabis pollen that acts as a defense mechanism to keep pests away. Kief is a popular “by-product” of weed consumption that is often used for edible creation.
If you decide to try kief decarboxylation, grind the cannabis into flakes and sift the kief away from the plant parts. It takes a little while, so exercise patience and diligence.
Kief tends to decarb faster than bud, meaning you can afford to employ a lower temperature. Once you have spread it over the baking sheet, follow the steps mentioned earlier in the article. Place the kief on a parchment sheet, and put it in the oven at between 240 and 300 degrees Fahrenheit (115 – 150 degrees Celsius). It should be fully decarboxylated after 45-60 minutes.
Final Thoughts on Decarboxylation
Although it is one of the most important parts of enjoying marijuana, decarboxylation is also one of the least understood. If you aim to use cannabis recreationally or fully benefit from the medical properties of the plant, most of the active components will need to be decarboxylated. THC-A must be transformed into THC, CBD-A into CBD, and so on.
When you light a joint or use a vaporizer, the process of decarboxylation occurs instantly. However, those who use cannabis in edibles have to go through a time-consuming decarb process to ensure their products are “molecularly active.” Although there is some merit to consuming raw cannabis, it offers few therapeutic (or recreational) benefits compared to the “decarbed” version.
Want to learn more? Decarboxylation is extremely important, but so is knowing how to dry and cure your harvested marijuana flower. Learn how to do it properly in our Complete Guide to Drying and Curing Cannabis Buds.