If you plan to make cannabutter and cannabis brownies using your favorite strain of raw cannabis flower, kief, shake, or trim, in order to get all the benefits out of your medical cannabis, you will need to decarboxylate it, first. By the way, just drying and curing it over time will cause some decarboxylation.
So, what is decarboxylation and why do you need to do it?
One of the major compounds of the cannabis plant is THC which is responsible for the psychotropic effects. In its raw form, the compound THCa is not psychotropic until you heat it to a certain temperature over a period of time. The process of applying heat or vaporizing cannabis triggers a chemical reaction that removes a carboxyl ring or group (COOH) and releases carbon dioxide (CO2). See visual at the top of this post.
The other thing to keep in mind is that the lower the temperature you set your oven and the longer it takes to decarboxylate, the more terpenes survive. Terpenes, which account for the color, flavor and aroma, provide many of the medicinal benefits in cannabis. Here’s the link to my post on Terpenes.
It seems there are several differing opinions on what temperature to set your oven and how long to decarboxylate your raw cannabis products. Here is a good starting guideline:
1. Preheat oven to 240 F/115 C
2. Using your hands, gently break up flowers and buds. In this example, we are using 1 ounce but you can use more or less
3. Place the pieces in one layer in a Pyrex dish, making sure there are no empty spaces
4. Cover tightly with aluminum foil
5. Bake for 60 minutes, stirring it every 10 minutes so that it bakes evenly.
6. When the color darkens to a light to medium brown and is completely dried, remove it from the oven and let it cool. It should be crumbly at this point.
7. Coarsely grind it in a food processor or grinder and store it in an air tight container
In addition, you may choose to place a pizza stone on the middle rack of the oven which absorbs the heat and helps maintain a constant temperature. You can also invest in a digital in-oven thermometer to monitor the temperature during the entire process. Place the thermometer on top of the pizza stone with the cord connecting to the digital readout on the counter next to the oven. There are also machines available that do all the work for you.