Cannabis Decarboxylation: 10 Burning Questions Answered

In this article, you will learn:

• What is decarboxylation?
• How does decarboxylation work?
• What is the best way to decarboxylate cannabis?
• Are there other cannabis decarboxylation methods?
• What is the optimal cannabis decarboxylation temperature?
• What about CBD decarboxylation?
• How do I decarboxylate kief?
• How do I decarboxylate shatter (BHO)?
• Will decarboxylation make my house smell like weed?
• What’s the best way to decarboxylate cannabis in an apartment?

1. What is decarboxylation?

Simply put, decarboxylation is the process of applying heat to cannabis in order to “activate” THC (and other cannabinoids) so that it can produce psychoactive effects when consumed. Cannabis decarboxylation is an important step in making edibles.

It might seem like a fancy word, but it’s not all that complicated. In fact, you already decarboxylate cannabis every time you light up a joint or take a puff from a vaporizer!

But why does THC need to be activated? Well, as it turns out, THC (tetrahydrocannabinol) is only found in trace amounts in fresh (unheated) cannabis flower. The most abundant cannabinoid in most cannabis strains is actually THCA – tetrahydrocannabinolic acid.

THCA, although non-psychoactive, has potential therapeutic applications that researchers have only recently started to discover. One study found that “THCA may be a more potent alternative to THC in the treatment of nausea and vomiting.”¹

So, if your goal is to get high, you’ll need to decarboxylate your weed before consuming it.

2. How does decarboxylation work?

In technical terms, decarboxylation is the removal of a carboxyl group from THCA. Wait… what?

If you weren’t paying attention in high school chemistry class, don’t worry – we’ll break it down for you.

As seen in the image above, a THCA molecule contains a cluster of atoms called a carboxyl group (denoted in red brackets). Carboxyl groups consist of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group (OH). When THCA is exposed to heat, a carboxyl group is removed and replaced with a single hydrogen molecule. As a result of this chemical reaction, C0₂ is also released.

Keep reading to learn how to decarboxylate weed.

3. What is the best way to decarboxylate cannabis?

When it comes to deciding how to decarboxylate cannabis, you have a few different options. We’ll get into those options in the next question, but the easiest and most common way to decarboxylate (or “decarb”) weed is the oven-and-tray method.

For this decarboxylation method, you’ll need:

• An oven
• A baking tray
• Parchment paper
• Dried cannabis flower

First, pre-heat the oven (ideal decarboxylation temperature is discussed in question 5). Coarsely grind your cannabis, then spread out evenly on a tray lined with parchment paper. Place in the oven for 30-45 minutes, then remove and let it cool down. Now your decarbed cannabis is ready to be infused into a high-fat substance and made into edibles! Try this cannabutter recipe if you’re unsure what to do with your decarboxylated weed.

4. Are there other cannabis decarboxylation methods?

Absolutely. Other decarboxylation methods involve using a mason jar, water or oil.

The mason jar method is a popular choice for folks who want to contain the smell that results from decarboxylation. While it won’t eliminate the odour, it might reduce it to an acceptable level. Moreover, decarbing weed in a mason jar lowers the possibility of burning your weed, since the warm air in the oven isn’t directly in contact with the cannabis. For this method, simply put your coarsely ground weed into a mason jar and place it on an oven safe mat during decarboxylation.

Another solution for how to decarboxylate weed is by using a slow cooker and water. For this decarboxylation method, place your ground cannabis into a slow cooker and fill it with water so that the weed is entirely submerged. Allow it to simmer for 30-45 minutes, then drain using a fine filter. One benefit to this method is ensuring a consistent temperature, since water boils at 212°F. However, full decarboxylation likely requires a higher temperature than this.

Some folks like to decarb their weed in oil. For this method, you can combine your weed with oil (coconut, olive, etc.) in a glass pie dish, then put it in the oven as you would with the baking tray method. This allows you to skip a step if you were planning to make canna-oil anyways, since you can keep the weed in the oil afterwards during infusion.

There’s also a plethora of decarboxylation devices you can use, which automate the decarboxylation process. Namaste doesn’t recommend any particular device, but with a little research you’ll find plenty of options.

5. What is the optimal cannabis decarboxylation temperature?

The perfect decarboxylation temperature is debatable; moreover, it will depend somewhat on individual preferences.

Thankfully, a study in 1990 examined different decarboxylation temperatures and the associated rate of conversion from THCA to THC.² As seen in the decarboxylation temperature chart above, to optimize THC content, a decarboxylation temperature of between 252-293°F should be used for 7-30 minutes.

This decarboxylation temperature chart should be used as a general guideline, not a concrete rule. Some folks like to decarb their weed at a lower temperature for a longer period of time. While this may not produce the highest possible amount of THC, it ensures other cannabinoids and terpenes (flavour compounds) remain intact by staying well below their boiling points.

6. What about CBD decarboxylation?

We mentioned earlier that the purpose of decarboxylation is to turn THCA into THC. While that is certainly the goal when decarbing high-THC strains, you may be interested in making edibles with a high-CBD strain instead. Like THC, CBD also comes in an acidic form – CBDA (cannabidiolic acid) – which must be heated in order to convert into CBD.

However, the ideal time and decarboxylation temperature is slightly different for high-CBD strains. One study found that the optimal CBD decarboxylation temperature is between 265-295°F, with full decarboxylation occurring after 30-40 minutes.³

7. How do I decarboxylate kief?

Kief decarboxylation is fairly similar to cannabis decarboxylation. After all, cannabis is simply plant matter covered in trichomes (kief).

To decarboxylate kief, simply follow the same instructions as used for dried flower. We don’t suggest using the water or oil methods for kief, however, as its granular consistency makes it very difficult to strain afterwards.

8. How do I decarboxylate shatter (BHO)?

Decarboxylation of shatter or BHO (butane hash oil) is best done in an oven with a pan. Line it with parchment paper and apply the sticky substance over top. If it’s high-THC shatter, follow the THC decarboxylation guidelines for temperature and cook time. Don’t be alarmed if you notice some bubbling – this is natural and results from the loss of water and C02.

If you’re making edibles with shatter/BHO, it’s especially important to start low and go slow. Shatter is a highly concentrated cannabis product designed for dabbing – one of many possible cannabis consumption methods.

9. Will decarboxylation make my house smell like weed?

Many consumers wonder how to decarboxylate weed without smell. Unfortunately, the odour is impossible to eliminate, but you can take steps to reduce it. At the end of the day, though, decarboxylating cannabis is likely to produce a strong odour.

10. What’s the best way to decarboxylate cannabis in an apartment?

Turn your oven’s hood fan on full blast during decarboxylation, and make sure to open all windows. It might not be possible to decarboxylate cannabis without smell, but you can lessen the odour.

Decarboxylation in an apartment might not be ideal if you have neighbours with a keen sense of smell.

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References:

1. Rock EM, Kopstick RL, Limebeer CL, Parker LA. Tetrahydrocannabinolic acid reduces nausea-induced conditioned gaping in rats and vomiting in Suncus murinus. British Journal of Pharmacology. 2013 Oct;170(3):641-8.

2. Veress T, Szanto JI, Leisztner L. Determination of cannabinoid acids by high-performance liquid chromatography of their neutral derivatives formed by thermal decarboxylation: I. Study of the decarboxylation process in open reactors. Journal of Chromatography. 1990 Nov;520:339-347.

3. Wang M, Wang YH, Avula B, et al. Decarboxylation Study of Acidic Cannabinoids: A Novel Approach Using Ultra-High-Performance Supercritical Fluid Chromatography/Photodiode Array-Mass Spectrometry. Cannabis and Cannabinoid Research. 2016;1(1):262–271.