How do you decarboxylate medical marijuana?

The predominant compounds found in cannabis are THCA and CBDA. THCA is the major cannabinoid inCannabis, while CBDA predominates in fiber-type hemps. THCA and CBDA accumulate in the secretory cavity of the glandular trichomes, which largely occur in female flowers and in most aerial parts of the plants. The concentration of these compounds depends on the variety of cannabis and its growth, harvesting and storage conditions. When locked in their acidic forms, THCA and CBDA are not bioavailable to the body’s cannabinoid receptors. Occurring either naturally within the plant, or upon “decarboxylation” (heating the plant material), these acids are non-enzymatically decarboxylated into their corresponding neutral forms (THC and CBD).

THCA is non-psychoactive (meaning it does not produce mind and body altering effects). If you want to achieve the full psychoactive effects of your butters, fats, oils, sugars or alcohols, decarboxylating the plant material to convert the THCA to THC prior to infusion is essential. Control of heating temperatures and times is critical when cooking with cannabis. Heating cannabis also converts THC to CBN. At about 70% decarboxylation, THC is converted to CBN at a faster rate than the THCA is converted to THC. Higher CBN levels will produce more sedative effects. There is much debate and opinion on this process and very little scientific evidence to establish the best method of decarboxylation.

Forewarning: There will be a very strong odor of cannabis during this process.

1. Preheat oven to 225° F / 110° C.
2. Line an oven-safe dish (or a rimmed baking sheet) with parchment paper.
3. Breaking up cannabis buds into smaller pieces by hand, place the material in the dish close together but not stacked on one another (the less unused space the better).
4. When oven is pre-heated, bake for about 20 minutes to remove the moisture (depending on the freshness of the material). Watch for the plant color to get darker (a light to medium brown shade). When it is time to remove from the oven, the material should be crumbly looking.
5. Set plant material aside and wait until it is cool enough to handle. Turn oven up to 240° F / 115° C and wait for it to preheat again.
6. When the cannabis is cooled, lightly crumble by hand and distribute evenly over the bottom of the dish.
7. Cover dish with aluminum foil, crimping the edges tight to seal and return to the oven. Continue baking for another 45-60 minutes for higher THC and 60-90 minutes for higher CBD.
8. Remove from oven and allow to cool fully before removing the foil. Depending on the material you use, it may be fine enough and require no further processing. If not, you can place the material in a food processor or blender, pulsing the cannabis until it is coarsely ground. Be careful not to over grind the material, as you do not want a super fine powder.
9. Place in an airtight container (glass preferred) and store in a cool, dry place.

Click here to learn more about the decarboxylation process and how it applies to cooking with cannabis.