Decarboxylation. DO NOT let the long scientific name intimidate you and scare you off from reading this article. If you use cannabis and ESPECIALLY if you cook with cannabis, this tutorial on marijuana decarboxylation is vital information you need to know in order get the most out of your cannabis.
Don’t worry, I am going to break everything down in layman’s terms to make it easy to understand and to do.
What is marijuana decarboxylation?
Scientifically speaking, Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2).
So why the heck should cannabis users care about this? Because if you want to feel a buzz from your cannabis, you need it to be decarboxylated. Why? Because believe it or not, the raw cannabis plant contains no THC!
Raw cannabis contains the acidic form of this cannabinoid, THC-A or Tetrahydrocannabinolic Acid, which will not make you high. It takes the process of age and/or adding heat to decarboxylate the cannabis and convert the THC-A into psychoactive THC or Tetrahydrocannabinol.
All the cannabinoids contained in raw cannabis flowers have an extra carboxyl ring or group (COOH) attached to their chain, so decarboxylation works with more than just THC, although this is where its effects will most be felt by the end cannabis consumer as the other cannabinoids don’t make you high.
What causes decarboxylation?
Time and heat are the two main catalysts that cause decarboxylation, but mostly heat. It’s true that over time, some decarboxylation will occur, but not a lot. This is why some raw flowers will lab test positive for some THC, although THC-A will be far more prevalent.
Of course when you smoke or vape marijuana, decarboxylation naturally occurs due to the heat of the flame or heating element. But according to expert Shanel Lindsay, inventor of the Ardent Decarboxylater, smoking or vaping flowers that have been decarboxylized first will up your high’s potency! I know most people don’t do this, but it’s something to consider.
You might also come across the term “activate” the cannabis, which also means to decarboxylate it.
Why do you need decarboxylation?
Besides the fact that you need decarboxylation if you want to get high from your cannabis, it also unlocks the full medicinal potential of other cannabinoids, such as CBDs, CBNs, and CBGs. Now to be sure, the acidic form of all these cannabinoids also have important medicinal benefits, so if a high is not important to you, full decarboxylation may not be either.
So what do I mean when I say “full decarboxylation?” This would mean you are converting 100% of the THC-A in your plant material into THC. This is nearly impossible for reasons I’ll discuss in the next section, but know that usually some is left unconverted.
Does it matter? To a degree yes, but in my opinion not as much as a lot of people think it does. I say this because unless you are ultra sensitive to THC you probably are not going to notice a few points difference. And the THC-A left unconverted is imparting health benefits, so it’s not a big loss.
I also say this because, long before lab tests showed that decarbing before making slow cooking infusions like butter and oil increases potency, we still made some potent AF infusions. Many people still do not bother to decarb before making these infusions and still get great results.
That said, most people do want to get as much potency as possible from their cannabis, so they are going to want to convert as much THC-A into THC as possible, which means they are going to want to know how to decarboxylate their marijuana. And not just flowers – kief, hash, and hash oils all benefit from decarboxylation as well.
What types of marijuana need to be decarboxylated?
Marijuana in most of its forms will benefit from decarbing. Of course flowers/buds and trim, but also kief, and hash. Most hash oils have not been decarbed either, so if you cook with these, know that you will want to decarb first.
How to decarboxylate marijuana
Consult 10 difference sources and you’ll find 10 different methods for how to decarboxylate your marijuana. I tried to get some testing labs and scientists to go on record with the best times and temperatures for decarbing and could not get a straight answer out of any of them. Perhaps this is because, like so many things with cannabis, there is no one simple answer. For instance, the amount of moisture in your plants can significantly affect the time needed to decarb, with more time needed for drying, and then decarbing. Or that decarbing CBD-A takes more time than decarbing THC-A.
After researching lots of methods, especially those that have been lab tested, my own views on decarbing have evolved. While I used to recommend about 20 minutes at 220 degrees F, I know see that a much longer decarb time can achieve far greater THC conversion. So I now recommend about an hour at 240 degrees F. thanks to the fine folks at the Marijuana Growers Headquarters who did some experiments and lab testing.
Place your cannabis or cannabis concentrate in an ovenproof dish, or on a baking sheet if you are decarbing a lot of plant material. Cover with foil and place in a preheated 240 degree oven for about an hour. Your cannabis is now decarbed and ready for cooking. You will notice that it appears and smells a bit “toasty.” You may also notice that you lost a little volume. This is normal. The photo above show the same strain and amount of cannabis after (left) and before (right) decarboxylating.
Interestingly enough, the experiments done by the Marijuana Growers Headquarters did not convert much of the CBD-A to CBD. Probably because as a general rule CBD needs longer to decarboxylate.
CBD concentrates or isolates may or may not be decarbed already, although most are, so check the labels to see if this step is necessary. If it lists a high CBD content (as opposed to CBD-A) it has been decarbed.
According to the experts at Sensi Seeds you should decarb high CBD cannabis strains (defined as 90% or more of total cannabinoid content) for 15 minutes at a temperature of 220°F in order to dry the plants, and then 60 minutes at 250°F. for decarboxylation. As oils and isolates don’t need drying, I would just go with the 60 minutes at 250°F. for these, if needed at all.
According to Project CBD’s Martin Lee, there is no exact boiling point number for CBD, but it is in the 320°F – 338°F range, slightly higher than THC.
When using the Ardent Nova Lift Decarboxylator, inventor Shanel Lindsey recommends putting the cannabis through two decarbing cycles, IF (and ONLY IF) the plant matter contains under 1% THC, otherwise decarb CBD in the same manner as THC.
Keep in mind CBD, like THC, metabolizes better in the presence of fat, so it best to use in recipes that contain fat, or alternately consume nonfat CBD edibles accompanied by a fat containing food or beverage.
Is it always necessary to decarboxylate even if you will be cooking with the cannabis anyway?
For maximum potency, it is preferable, yes. If you are just stirring kief or hash oil into a brownie batter or other such cooking tasks you will DEFINITELY want to decarb first to get more potency. But lab tests show that even when making long, slow cooking infusions like marijuana butter and cannabis oil, decarbing first can help you achieve more potency.
What Happens When you Don’t Decarboxylate?
You still get medicinal benefits but you won’t get high, or at least you won’t get as high, depending on how much of your cannabis was decarbed through age or the heat of cooking.
Remember, THC-A still has important medicinal qualities including being a neuroprotectant and anti-inflammatory agent
In short, you will have lower potency, but you will still have perfectly usable edibles in most cases, as I talk about in this video.
The importance of marijuana decarboxylation when calculating cannabis edibles dosages
For those who have taken my free online Edibles Dosing Class and use my edibles dosage calculator tool, proper marijuana decarboxylation is important in order to get accurate dosing estimates. If you fail to convert a majority of the THC-A to THC your dosing estimates will be high and you may be disappointed in the potency of your finished product. Generally speaking I usually estimate a few points less than the calculator says in order to make up for some THC-A that may remain unconverted.
What can go wrong when decarboxylating?
Ovens are notoriously inaccurate when it comes to temperature, and they can have hot and cold spots. Use an oven thermometer and check the temperature before decarbing. Make sure it really is 240 degrees, no matter what temperature you set the dial to. My friend’s oven was a whopping 100 degrees off so do not skip this important step. Too little heat and you won’t activate enough of the THC, too much heat and you can kill it.
As we have also discussed, a lot of moisture in your cannabis can make it take longer to decarb. If you are working with fresh, wet cannabis, try adding another half hour or so to your decarb time. Same if you are decarbing a high CBD strain.
How to Decarboxylate Weed
Aside from smoking or vaping, there are many 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 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. However, please note that 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, you’ll likely get twenty different answers. We can tell you that the lower the decarboxylation temperature, the longer the chemical process takes. But few people realize that if decarboxylation temperatures are too high for too long, you risk ruining the herb’s active ingredients.
There is a dispute over the exact decarboxylation temperature of CBD. According to studies, 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 more extended period – typically between 40 and 60 minutes – is required 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 their decarb temperatures:
- CBC: 428 degrees Fahrenheit/220 degrees Celsius
- THC: 314 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: 150 degrees Fahrenheit/177 degrees Celsius
- Linalool: 388 degrees Fahrenheit/198 degrees Celsius
- Alpha-pinene: 312 degrees Fahrenheit/156 degrees Celsius
Flavonoids and Phytosterols
- Beta-Sitosterol: 273 degrees Fahrenheit/134 degrees Celsius
- Cannflavin A: 359 degrees Fahrenheit/182 degrees Celsius
- Apigenin: 352 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. Some compounds are volatile and evaporate at higher temperatures. The result is foul odors and an unpleasant taste. To preserve the 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. 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 cannabis and turn THC-A into THC or CBD-A into CBD, we convert THC to CBN faster. Once we reach 70% decarb, THC gets converted into CBN faster than the conversion of THCA into THC. In other words, when we go beyond 70% decarboxylation, THC levels start to fall off quickly. See the above chart for reference.
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. The temperatures used for kief, bud, or trim would be different. The graph was created in 1990 and involved decarbing a hexane extract in an open container on a hot plate. With modern equipment, it is possible to reach a 100% decarb without damaging your THC content.
Marijuana Growers HQ’s efforts went some way towards solving the mystery of the best decarbing temperature. In 2012, they tested cannabis trim and kief at 240 degrees for 30 and 60 minutes. The above table outlines the results.
They discovered that the vapor point of all significant terpenes, flavonoids, and cannabinoids was right around 246.2 degrees during their research. As consumer-grade ovens are not that reliable when reading temperatures, they played it safe by staying a few degrees below at 240 degrees.
According to the results, 30 minutes was not long enough to completely decarb the trim or the kief. The latter had reached 90%, but the former only managed 60%. Both were very close to 100% after an hour.
Decarboxylation Methods Investigated
Most assume 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 essential 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). While the max temp will preserve all compounds, the problem with this method is it’s impossible to achieve full decarboxylation.
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, causing degradation.
A product on the market called “Nova” claims to decarb cannabinoids with 100% efficiency. It provides lab tests to back up this claim. Therefore, it may be worth checking out if you’re dedicated to keeping the potency of your cannabis intact.
The other issue with decarb charts or graphs 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 the averages. Remember, you can’t place dry material in an oven 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 cannabis. It is essentially cannabis dust that acts as a defense mechanism to keep pests away. Kief is a popular by-product of cannabis consumption 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.
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 above. Place the kief on a parchment sheet, and put it in the oven between 240 and 300 degrees Fahrenheit (115 – 150 degrees Celsius). It should be fully decarboxylated after 45-60 minutes.
Decarboxylation is one of the least understood aspects of marijuana parlance. To fully benefit from cannabis, most of the active components first need to be decarboxylated. THC-A must be transformed into THC, CBD-A into CBD, and so on.
When you combust cannabis or use a vaporizer, the process of decarboxylation occurs instantly. However, those who prepare 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.