Raw cannabis contains a lot of THCA which is not psychoactive (and what's the fun in that?). When you smoke weed, the THCA molecule loses its carboxylic group (COOH) in the form of water vapor and carbon dioxide and becomes THC. Long story short, THCA becomes THC and your cannabis becomes psychoactive. This process is called decarboxylation or decarbing.
When you smoke or vaporize marijuana, the cannabis is decarbed by the heat. If you ingest cannabis and want the full psychoactive effect, you need to first decarb your cannabis before you cook with it.
The lower the temperature, the longer it's going to take to decarb your cannabis. Keep in mind that a lower temperature will allow you to lose fewer terpenes.
What are Terpenes?
Terpenes are the pungent oils that color your cannabis with distinctive flavors such as berry, mint, citrus and pine. There are many medicinal benefits to terpenes; some will successfully relieve your stress while others will promote focus and awareness.
Table: Decarboxylation Temperatures and Times
Plant Material Time
Kief / Hash Time
10 - 18 minutes
5 - 10 minutes
Hot oil bath
Until bubbles taper off
40 - 60 minutes
30 - 40 minutes
Boiling water bath
Flower / Buds
Preheat your oven (see table above). Use an oven thermometer to check the temperature.
Break down the large buds with your hands
Distribute evenly across the pan
Place in the oven
Check on it after 20, 30 and 40 minutes (don't open the door fully)
Make sure it's toasting evenly
After 40 minutes it should be done - golden brown
Preheat oven (see table)
Sprinkle hash/keif on pie plate, cover with silver foil and crimp foil along edge of plate. Place sealed dish in oven for (see table).
Remove plate and let it cool down slowly without removing cover to allow any vapors to reabsorb into cannabis.
Boiling Bag method:
Place the cannabis flower/keif/hash into a boilable cooking pouch. Seal it.
Place in boiling water for 90 minutes. Make sure water does not boil dry.
Take bag out of water. Let it slowly cool before opening.
Place heat proof container of cannabis oil into a cooking oil bath (canola oil works well). Heat cooking oil to 121C/250F.
Stir cannabis oil to break up bubbles.
Remove cannabis oil from heat when bubble formation starts to slow down — or leave on heat until all bubbles stop for increased sedative effect.