Marijuana Oil: Step-by-Step Guide to Preparation

The quality of marijuana oil depends largely on the quality of the cannabis used. Some aspects to consider are:

– Origin and condition of the material (e.g. no mold, avoid excess humidity).
– Virgin olive oil is recommended for its quality and stability. Olive oil has been shown to be a better solvent compared to alcohol (used in cannabis tinctures) for preserving cannabinoids and terpenes from cannabis (1). Quality coconut oil can also be used.

If possible, it is recommended to avoid refined oils (labeled as “mild”, “intense”, or refined) and seed oils (grape, sunflower, rapeseed). These oils have less stability than virgin olive oil and are less resistant to heating, which would shorten the shelf life of the final preparation (the oil “rancidifies” or degrades earlier).

Shred the buds evenly, with clean hands. To do this, you can use manual tools such as a grinder, so that the cannabis is crushed into smaller pieces, without leaving dust. It is not recommended to grind to pulverize, because very fine particles may be filtered out later.

Decarboxylation activates the cannabinoids, i.e. applying heat. Heat converts cannabinoids into their active forms (e.g. THCA is transformed into THC). This step is essential to convert cannabinoids into their active form, because if this transformation does not occur, the “raw” cannabinoids have very little affinity for the receptors of the endocannabinoid system in the body and do not have the desired effect.

To do this, preheat the oven between 105°C and 120°C with a glass of water, which will prevent the temperature from exceeding too much. Do not use the broiler, as it can increase the temperature by radiation and burn the shredded buds more easily. If you cannot remove the broiler, keep the oven tray on lower shelves.

Spread the crushed cannabis evenly on a baking sheet covered with parchment paper and bake at 105-120 ºC temperature for 30-45 minutes. Stir the cannabis every 10-15 minutes for even decarboxylation. Then remove the tray and allow the plant material to cool to room temperature. Respect the indicated times and temperatures.

Now that we have the cannabis with active cannabinoids, the next step is to extract them into a base oil. Cannabinoids, being lipophilic compounds, dissolve efficiently in fats.

We will need a heavy-bottomed pot or slow cooker and a cooking thermometer :

– Place the decarboxylated cannabis in the pot first and cover it with the base oil (olive oil is the most recommended).

– Stir to completely submerge all the cannabis in the oil, try not to leave any dried cannabis on the surface of the oil.

– Heat the mixture in the pot over very low heat, maintaining a constant temperature between 60 °C and 80 °C for 2 to 3 hours.

Time and temperature binomial: If the longest infusion time is chosen, it is recommended to keep the temperature in the lower range of 60 ºC. In the infusion of marijuana in oil it is crucial to avoid higher temperatures, which could degrade the cannabinoids and volatilize the terpenes, compounds responsible for the aroma and that modulate the effects of the oil. Control the temperature with a thermometer.

During the infusion time, the active cannabinoids are extracted from the marijuana, as well as terpenes and flavonoids, components that enhance the effects of the cannabinoids, in what is known as the cannabis entourage effect – the synergy between different compounds.

Some recipes opt for a longer infusion of up to 6 hours, but this is not recommended. Exceeding time or temperature could reduce the potency of the final product by degrading THC into CBN (cannabinol), a THC derivative with distinct properties. In addition, it could compromise the stability of the oil (the fats that make up the oil may go rancid prematurely, shortening the shelf life of the cannabis preparation).

Once the infusion time is over, and without letting it cool for too long, separate the oil from the plant material to obtain a quality extract and to optimize its conservation. When the oil is warm, it is much easier to filter. In addition, if left to cool for too many hours, the plant material could release unwanted aromas into the oil. It could even be done with hot oil, just be careful to use a fine metal strainer and not to burn yourself when handling it.

We will need:
– Thin metal strainer or a cheese cloth (muslin),
– Glass container to store the marijuana oil,
– Wooden spatula

Instructions:
– Place the fine strainer or a cheese cloth over a glass container.
– Carefully pour in the hot mixture, allowing the oil to seep through and leaving behind the remnants of the cannabis.
– Using the wooden spatula, gently press down on the plant material to “squeeze” it and extract as much of the oil as possible.
– Cover with a gauze or napkin to keep dust out. Allow the filtered oil to cool completely before sealing and storing.