THCa Flower and Decarboxylation: Transform Your Hemp

Hands passing a high THCa flower joint. Thca flower and decarboxylation: Transform your hemp. Earthy Select

Many cannabis consumers enjoy the psychoactive cannabinoid Delta-9 THC, or Delta-9 tetrahydrocannabinol, for its recreational and therapeutic rewards. However, this coveted cannabinoid is sometimes not readily present in the flower buds of particular cannabis strains, unless the plants undergo a process called decarboxylation. In other words, when it comes to THCa flower and decarboxylation, you can transform your hemp.  

Tetrahydrocannabinolic acid, or THCa, on the other hand, is the precursor to THC and is often abundant in many cannabis strains when they are freshly harvested. Although THCa may have the potential for its own therapeutic benefits, it will not produce a high, that is, unless it is decarboxylated, or heated properly.

Read on to find out the easiest and most efficient ways to transform your THCa into THC through decarboxylation.

What is THCa?

Though it might be hard to use this word in a game of Scrabble, THCa is short for tetrahydrocannabinolic acid. THCa is simply the acidic form of Delta-9 THC.

THCa is non-psychoactive yet is enjoyed for other potential benefits. But, THCa changes when its temperature elevates through a process called decarboxylation, transforming it into the much sought-after Delta-9 THC [1]. 

Thus, smoking or vaping cannabis high in THCa is an easy and popular way to turn the cannabinoid from a non-psychoactive one into one that will initiate psychoactive effects in the body’s endocannabinoid system. But smoking and vaping are not activities in which all THC enthusiasts wish to partake. Fortunately, there are other ways to accomplish the decarboxylation reaction of THCa.

What is the THCa decarboxylation process?

Think of decarboxylation as a way to activate the cannabinoids in raw cannabis into more potent forms. Scientifically speaking, decarboxylation is the process whereby the chemical structure of a cannabinoid is altered from its acidic to its non-acidic form. When THCa is altered in this way, it is turned into Delta-9 THC.

Freshly harvested cannabis contains many cannabinoids found within the flower trichomes, some of which contain an extra carboxyl ring attached to their molecular chain. THCa and CBDa both have this extra carboxyl ring. In essence, the process of decarboxylating cannabis removes that carboxyl ring from the initial chemical structure.

Even when fresh cannabis dries and cures after harvest, some natural decarboxylation occurs. However, hotter temperatures will increase its reaction rate triggering the transformation of more cannabinoid acids. For instance, when THCa is smoked or vaped, decarboxylation into Delta-9 THC is virtually instantaneous [2].

Decarboxylated cannabis versus raw cannabis

Raw cannabis refers to a cannabis plant that is undried, uncured, or unprocessed. On the other hand, when the plant is dried or cured, the shelf life will extend and chemical changes will begin to occur slowly. Some people enjoy utilizing raw, freshly harvested cannabis as an ingredient for smoothies, oils, or tinctures, yet freshly harvested cannabis needs to be used quickly or it will spoil. That’s why most cannabis is dried and cured soon after harvest.

Moreover, this drying and curing process prepares the plant for consumption by jump-starting decarboxylation. With THCa, for example, the acidic cannabinoids will slowly begin to change to the psychoactive Delta-9 THC as the plant dries, yet this process will advance further if the plant is heated by smoking, vaping, or cooking [3].

The Farm Bills and the legality of cannabis

Until the legislation of the 2014 Farm Bill, hemp was a Schedule 1 controlled substance. Yet, the Bill removed hemp from this list and made hemp, which was designated as cannabis with 0.3 percent or less Delta-9 THC, federally compliant. Long-forbidden research commenced after almost a century of prohibition, opening the door for further legislation.

Four years later, the 2018 Farm Bill allowed the production, sale, and consumption of hemp-derived products. At this point, legal experts assured growers, producers, and consumers that all plant materials and substances derived from legally-defined hemp were now federally compliant [4]. Of particular relevance to this article, even hemp flower with high levels of THCa falls under this category of federally compliant hemp, which was allowed by the 2018 Farm Bill.

To this day, federal law defines cannabis plants with less than 0.3 percent concentration of Delta-9 THC per dry weight as hemp plants and allows hemp production and consumption in all 50 states. The DEA only tests for Delta-9 THC at the exclusion of other cannabinoids, including THCa, when determining their status after harvest.

In contrast, cannabis plants with more than 0.3 percent Delta-9 THC per dry weight are defined as marijuana, which federal law continues to treat as a controlled substance on the DEA’s Schedule 1 list. Yet in the past few years, many states have come to allow medical use and/or adult recreational use of marijuana.

Though not considered for the DEA’s hemp compliance determination, THCa falls into legal gray area. On the one hand, THCa is not psychoactive. On the other hand, it is derived from cannabis and, when heated, will convert to THC.

The legality of THCa

So, is THCa legal? The simple answer is yes. It is lawful under the Farm Bill even if it might later convert to Delta-9 THC when heated. Why? Because the DEA only tests for Delta-9 THC when considering if a plant is hemp or marijuana. Indeed, THCa is one of the hundreds of non-psychoactive cannabinoids not tested for when determining the status of federally compliant hemp. Surprisingly enough, the DEA does not seem to care whether or not the cannabis in question first passed the USDA pre-harvest “total THC” test. At the end of the day, if a cannabis product contains less than 0.3 percent Delta-9 THC, it is considered federally compliant.

How could a plant that is as psychoactive as marijuana be legal? The short answer is because: the USDA tests for “total THC” content only before it is harvested, and then the DEA only tests for Delta-9 THC after it is harvested. So, when the DEA tests to ensure a plant is federally compliant, it will be considered hemp versus marijuana if its Delta-9 THC level falls below the 0.3 percent threshold. The THCa will not be counted.

The guidelines for assessing marijuana for regulated marijuana markets, on the other hand, can test for “total THC” content, including THCa. This means that, in certain scenarios, the same cannabis strain could be considered federally compliant hemp or as marijuana, depending on who’s testing it and whether it’s being tested for the marijuana or hemp markets [5].

But these legal nuances must be carefully considered by both sellers and consumers. For example, even if your THCa product is federally compliant, it’s possible that law enforcement officials and/or legal representatives may misinterpret the law and come to the conclusion that a THCa product with less than 0.3 percent Delta-9 is marijuana.

THCa versus THC: benefits and risks

Though there are usually few to no adverse side effects from consuming THCa products, if stomach upset occurs, be sure to stop taking it. The greatest risk in taking THCa, however, may be decarboxylating it by accident. In other words, if your raw cannabis has not been stored properly and has converted to Delta-9 THC, or if you smoke or vape it without realizing what will happen when it’s heated, you could become intoxicated by accident.

Therefore, it’s important to know how your cannabis will decarboxylate. You don’t want to find yourself experiencing unwanted intoxication when you were after the potential therapeutic effects of THCa. So, be sure to store your THCa products in a dry place away from any heat or direct sunlight and away from higher temperatures.

The difference between THCa, THC, and CBD

The main difference between THCa and Delta-9 THC is that the former is non-psychoactive until heated, and the latter is psychoactive. In contrast, Cannabidiol (CBD) is an entirely different cannabinoid with no psychoactive component, even though it also changes from CBDa to CBD after decarboxylation. CBD is associated with wide-ranging health and therapeutic benefits of its own, and research is still in its infancy.

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Maximizing THC from the THCa decarboxylation reaction

Raw or non-decarboxylated cannabinoid compounds are sometimes referred to as acidic cannabinoids. Cannabidiolic acid (CBDa), for instance, is a non-psychoactive cannabinoid and the acidic precursor to its more potent counterpart CBD. Likewise, THCa is non-psychoactive until it undergoes thermal decarboxylation, where it is converted into Delta-9 THC [2].

Clearly, people who want the psychoactive effects of their cannabinoids will be interested in how they can get the most out of their cannabis. This means they can either smoke or vape their cannabis to experience the effects of the THC, or heat it in other ways. Yet, if it is not heated enough, it could mean that some of the THCa remains in the cannabis as neutral cannabinoids. On the other hand, if it is heated too much or too long, there will be a significant loss of the cannabinoids’ potency [2].

Decarboxylating THCa plant material for edibles, topicals, and oils

It’s good news for non-smokers and non-vapers that THCa can easily be decarboxylated without engaging in these activities. Cannabis can be heated in your oven or even your microwave, but it has to be done right in order to preserve the concentrations of cannabinoids. Some people even add it directly to food or oil as they cook their food, but it is more difficult to control the appropriate temperatures and amount of time heated. 

We’ll describe some of these in situ monitoring methods below [2].

Decarboxylating cannabis in your oven

Cooking cannabis in an oven is the most popular way to decarboxylate at home. Follow these steps to transform your cannabinoids in your oven:

  • Preheat your oven to 250°F. (Keep in mind there will be a strong cannabis aroma in your house for several hours after.)
  • Use parchment paper to line a baking sheet. The parchment paper will make it easier to collect and store your decarboxylated cannabis after baking.
  • Rip the buds of your cannabis into small pieces. Some people prefer to grind it before decarboxylation.
  • Bake the cannabis for 25-30 minutes. Do not bake at higher temperatures or for longer amounts of time or there will be some decomposition of the cannabinoids.
  • After the time is up, remove the trays from the oven and allow the cannabis to cool fully. You will notice that it will have changed from green to beige.
  • Collect the decarboxylated cannabis and put it into an airtight glass container, like a jar.
  • Ultimately, place the container of decarboxylated cannabis in a place far from heat sources, in a dark, cool spot.
  • It’s best to use your cannabis to make oils, salves, or other edibles within three to six months in order to preserve the potency of the cannabinoids.

Decarboxylate cannabis in your microwave

Not the preferred method of discerning decarbaoxylators, but in a pinch, a microwave can allow you to yield your preferred cannabinoid quickly. However, some people claim that microwaves degrade cannabinoids and terpenes and make temperature and time harder to control than ovens.

Nonetheless, if you find yourself without the use of an oven and decide to decarboxylate by microwave, choose a tightly lidded container with three layers of kitchen towels. Spread the ripped-apart cannabis on the first cloth in 1-centimeter pieces, and cover the cannabis with the remaining slightly damp sheets. Then, place on the lid, leaving one a bit open [6].

Cook at 300 watts for one minute, but success depends on the differences between microwave ovens. For cannabis perfectionists, the ease and speed of microwaving will not outweigh the risks of cannabinoid potency or flavor loss.

Decarboxylation method via “sous-vide”

This method is an attractive one for its low-risk and smell-free advantages. However, you’ll need special equipment to decarboxylate in this way, namely a sous-vide cooker. Decarbing sous-vide involves vacuum-packing your cannabis in plastic and heating it in water. The technique was first used for a type of French cooking and required expensive equipment. But now, this technique is much more affordable and inexpensive sous-vide cookers can be found.

Follow these directions for sous-vide decarboxylation [6]:

  • Divide your cannabis into chunks.
  • Pack the pieces in a heatproof plastic bag using the vacuum sealer.
  • Install the sous-vide cooker and set the temperature to 95°C.
  • When the water has reached this temperature, put the bag of cannabis in the water and leave it for one hour.

Where can you buy THCa Flower?

Ready to buy THCa flower? You can order THCa Flower online from Earthy Select! Get ready for powerful effects with superb quality and flavor in each of Earthy Select’s premium THCa strains. We ensure that care is taken with full traceability from seed to shelf. Every harvest is hand inspected and each strain is third party lab tested at approved facilities to ensure purity and potency. All of our THCa hemp flower is federally-compliant with the US Farm Bill.

Key takeaways for THCa and decarboxylation

For some, smoking or vaping cannabis is a great way to activate the latent Delta-9 THC waiting to emerge within your cannabis’ THCa. Yet, for others, these rituals may not be ideal, especially for those wanting to avoid the potential health risks associated with smoking or vaping. The solution for people hoping to turn their THCa into Delta-9 THC is to ensure proper cannabis decarboxylation before making any edibles, oils, or infusions to get the most bang for your buck.

Learn more: What Is the Future of THC?

Medical Disclaimer / Legal Disclaimer – Information is provided for educational purposes. It does not and is not intended to constitute legal advice or medical advice. We attempt to be accurate and up-to-date, but the legality of cannabinoids and the science of cannabis are evolving. The author is neither a legal professional nor a medical expert. Before buying or using any products, you should check with your local authorities and medical providers.


  1. Tetrahydrocannabinolic Acid
  2. How to Decarboxylate Cannabis
  3. Understanding Raw vs Decarbed Cannabis
  4. HIA Position Statement on Delta-8 and Hemp Cannabinoids
  5. THCa Flower – The Next Big Thing in Hempland
  6. Decarboxylating Cannabis from THCa to THC

Frequently Asked Questions

THCa is the precursor to THC, and transforms into THC when decarboxylated.

THCa is not a federally controlled substance. It is the non-psychoactive chemical precursor to THC. Delta-9 THC is a federally controlled substance.

THCa diamonds are a form of THCa concentrate that can be smoked or vaped. They appear as solid crystalline structures and are semi-transparent. THCa diamonds are one of the purest forms of cannabis concentrates.