Marijuana Decarboxylation: Why and How to decarb your Cannabis Plant

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Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carboxylation, the addition of CO2 to a compound. Enzymes that catalyze decarboxylations are called decarboxylases or, the more formal term, carboxy-lyases (EC number 4.1.1).

In organic chemistry

The term “decarboxylation” literally means removal of the COOH (carboxyl group) and its replacement with a hydrogen. The term relates the state of the reactant and product. Decarboxylation is one of the oldest organic reactions, since it often entails simple pyrolysis, and volatile products distilled from the reactor. Heating is required because the reaction is less favorable at low temperatures. Yields are highly sensitive to conditions. In retrosynthesis, decarboxylation reactions can be considered the opposite of homologation reactions, in that the chain length becomes one carbon shorter. Metals, especially copper compounds,[1] are usually required. Such reactions proceed via the intermediacy of metal carboxylate complexes.


In conclusion


• Loss of carbon dioxide is called decarboxylation.
• Esters or carboxylic acids  with a carbonyl group at the 3- (or b-) position readily undergo thermal decarboxylation.
• Decarboxylation was first encountered in Chapter 19 for carboxylic acids (review).
• The reactive species is the carboxylic acid or the carboxylate anion.









The Chemistry Of Cannabinoids


The raw bud of every marijuana plant contains a variety of cannabinoids, including THCA and CBDA.

In their natural state, THCA and CBDA don’t interact with the body in the familiar ways. THCA won’t get you high and CBDA won’t provide the potent medical benefits we’re used to. That’s not to say that the medical benefits of the CBDA in raw marijuana disappear completely.

Some patients do see results just by drinking juices or smoothies containing raw cannabis. And the raw herb does contain vitamins and nutrients just like in other leafy greens. But the body uses that CBDA differently than it would the CBD.

To really get therapeutically significant effects , we have to activate the cannabinoids through a process called


Think of drying as nature’s way of giving you a good trip. In fact, drying cannabis is probably the original way that early ganja aficionados activated their weed. They didn’t have our fancy ovens or climate-controlled rooms. They just hung the herb up to dry in the sun.

During the drying process, the heat from the sun caused a small amount of THCA and CBDA to chemically transform into THC and CBD. It was a natural process that prepared the cannabis for the next stage:

But drying doesn’t release the full potential of the cannabinoids. For that we need another step: decarboxylation.


To fully understand decarboxylation, we need to break the word into its constituent parts.

The first term, “de-”, is a prefix that basically means removal. The second term, “carboxyl”, is a chemical term for the acid radical group COOH which is found in most organic substances. The third term, “-ation”, is a suffix that basically means an action. Put those three terms together and you get, “the action of removing the carboxyl group (COOH)”.

Take a look at the image below. You’ll see a typical THCA molecule on the left. On the right, you’ll see a typical THC molecule after it has been decarboxylated.


But how do you go about decarboxylating (or decarbing) your cannabis? The same way the ancients did it—through the application of heat.


So you’ve got your dried buds on the table in front of you. You’ve ground the buds into small pieces in preparation for consumption, and you’ve rolled the grounds into a joint. You’re ready to smoke.

But remember, the dried bud in your joint is basically raw and won’t get you very high (if at all). So how does the weed go from the state it’s in now to the psychoactive powerhouse that it is when it hits your lungs? One word: fire.

When you apply a flame to your joint, or to the cannabis in your bong,  immediate decarboxylation occurs. THCA is converted to THC and carbon dioxide (CO2) is given off as a by-product. At the same time, the solid marijuana is vaporized (burned) and the whole kit-and-kaboodle, THC and all, is inhaled. From your lungs, the THC, and other cannabinoids, travels to your brain where it causes the wonderful psychoactive effects that we’ve come to know and love.

Eating Weed


If you decide to eat your weed instead of smoking it, you’re going to have to wait a little bit longer. Remember that burning the cannabis is basically immediate decarboxylation that transforms the inactive cannabinoids (THCA and CBDA) into their active counterparts (THC and CBD). But, at this point, you can’t light your buds on fire or there wouldn’t be anything left with which to cook.
You’ve got to decarboxylate your cannabis in another way. The easiest, most convenient way to do that is in an oven. But at what temperature should I set the oven? And how long should I let the buds bake? Two excellent questions that bring us to another important variable: terpenes.



Terpenes are those oils that give the cannabis plant its unique smell. There are a wide variety of terpenes and terpene combinations that create the various odors and tastes—sour, bitter, sweet, spicy, and all their variants—that distinguish one cannabis strain from another. In addition, terpenes work in tandem with the cannabinoids to increase the medical effects and effectiveness.

Going back to the decarboxylation process for a moment, we could just crank up the oven to 450℉ and bake for 5 minutes. However, that would destroy all the terpenes that give your favorite strain its character. Terpenes begin to break down above 310℉ so we want to stay away from those high temperatures.
And because we can’t use high temperatures, the cooking time is going to increase so that decarboxylation has the opportunity to work its magic. So let’s get to the step-by-step recipe for getting the most out of your cooking weed.

How To Decarboxylate Your Weed

1 Preheat oven to 230℉.
2 If you haven’t already, break up the dried buds into small pieces with your hands.
3 Spread the small pieces and flakes on a baking sheet (one with a rim works best).
4 Bake the cannabis at 230℉ for 35 minutes.
5 Stir the cannabis every 10 minutes to ensure even toasting.
6 After 35 minutes, check the cannabis. It should be light- to medium-brown in color and should be very dry. If it’s not, put it back in the oven for a further 5-10 minutes. Keep an eye on everything so it doesn’t burn.
7 When finished baking, remove the cannabis from the baking sheet and let cool. Careful, it’s going to be very crumbly at this point.
8 When the cannabis has cooled sufficiently, put it in a food processor and pulse until the weed is coarsely ground (like oregano).
9 If you’re going to use this marijuana in smoothies or drinks, you can continue grinding until you produce a powder.


Cannabis can also be activated through solvent extraction and ice-water extraction. These methods produce a concentrate that can be hardened and used for dabbing or kept in an oily state and used for cooking.

The important point of all this is that the cannabinoids in the marijuana need to be chemically altered (or activated) so that the body can process them easier. It’s this activation that gives your weed the psychoactive and medical benefits you crave.











Decarboxylation Explained

All cannabinoids contained within the trichomes of raw cannabis flowers have an extra carboxyl ring or group (COOH) attached to their chain. For example, tetrahydrocannabinolic acid (THCA) is synthesized in prevalence within the trichome heads of freshly harvested cannabis flowers. In most regulated markets, cannabis distributed in dispensaries contains labels detailing the product’s cannabinoid contents. THCA, in many cases, prevails as the highest cannabinoid present in items that have not been decarboxylated (e.g., cannabis flowers and concentrates).

THCA has a number of known benefits when consumed, including having anti-inflammatory and neuroprotective qualities. But THCA is not psychoactive, and must be converted into THC through decarboxylation before any effects can be felt.

The two main catalysts for decarboxylation to occur are heat and time. Drying and curing cannabis over time will cause a partial decarboxylation to occur. This is why some cannabis flowers also test for a presence of small amounts of THC along with THCA.

Smoking and vaporizing will instantaneously decarboxylate cannabinoids due to the extremely high temperatures present, making them instantly available for absorption through inhalation.

While decarboxylated cannabinoids in vapor form can be easily absorbed in our lungs, edibles require these cannabinoids present in what we consume in order for our bodies to absorb them throughout digestion. Heating cannabinoids at a lower temperature over time allows us to decarboxylate the cannabinoids while preserving the integrity of the material we use so that we may infuse it into what we consume.


Dosing Homemade Cannabis Edibles: Why It’s Nearly Impossible to Calculate Potency

At What Temperature Does Decarboxylation Occur?

The THCA in cannabis begins to decarboxylate at approximately 220 degrees Fahrenheit after around 30-45 minutes of exposure. Full decarboxylation may require more time to occur. Many people choose to decarboxylate their cannabis at slightly lower temperatures for a much longer period of time in attempts to preserve terpenes. Many mono and sesquiterpenes are volatile and will evaporate at higher temperatures, leaving potentially undesirable flavors and aromas behind. The integrity of both cannabinoids and terpenoids are compromised by using temperatures that exceed 300 degrees F, which is why temperatures in the 200’s are recommended.
Heat and time can also cause other forms of cannabinoid degradation to occur. For example, CBN (cannabinol) is formed through the degradation and oxidization of THC, a process that can occur alongside decarboxylation. CBN accounts for a much more sedative and less directly psychoactive experience.


What Is CBN and What Are the Benefits of This Cannabinoid?

How to Decarboxylate Cannabis at Home

In order to decarboxylate cannabis at home, all you need is some starting material, an oven set to 220-235 degrees F (depending on your location and oven model), some parchment paper, and a baking tray. Finely grind your cannabis until the material can be spread thin over parchment and placed on your baking sheet. Allow the cannabis to bake for 30-45 minutes, or longer if desired.
Cannabis can also be decarboxylated in a slow cooker by introducing solvents such as cooking oils or lecithin.These methods create infusions that can be used in a variety of cooking recipes, topicals, and even cannabis capsules. Since they contain decarboxylated cannabinoids, they will be effective any way you choose to consume them.












How to Decarboxylate Cannabis | Chef Melissa Parks

Start at: 0:00

Published on Apr 19, 2015
In this video, chef and edibles expert Melissa Parks explains how to decarboxylate your cannabis before cooking with it. “Decarbing” cannabis releases the full psychoactive effect.

The full recipe is at


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