When preparing marijuana to be eaten, made into a tincture, or some other method of ingestion other than smoking or vaporizing, it must first be decarboxylated.
This is done so the active components of marijuana will be more easily absorbed by the human body. This page is for working with marijuana buds, instructions for trim or shake are here.
Many people try to make some type of marijuana food or drink, only to have the resulting product provide very little psychoactive effect.
The most common cause is not decarboxylating the marijuana enough, or in some cases not decarboxylating at all.
When a marijuana plant is harvested, most of the THC (tetrahydrocannabinol, the primary active cannabinoid in marijuana) is in its acidic form. This is called THCA (tetrahydrocannabinolic acid). THCA is not psychoactive to humans.
Curing and drying causes some of the THCA to convert into THC. Smoking or vaporizing also causes THCA to convert into THC.
So when smoking or consuming it in a manner that heats the marijuana to a high temperature, some or most of THCA is converted to THC with no extra effort.
When eaten or drunk, an extra step called decarboxylation must be employed. This is accomplished by heating the marijuana under specific conditions prior to incorporating it into a recipe, or consuming it another manner.
The directions described below work best for me, but it is suggested that prior to decarboxylating marijuana yourself for the first time, you research other methods. Some people recommend different temperatures and different lengths of cooking time.
The first step is to decide how much marijuana to decarboxylate. If you are not sure, 7 grams of flower tops (marijuana buds) is a reasonable amount for a first attempt.
After you decide how much marijuana to decarboxylate, the next step is to grind it with an herb grinder, or some other method that you are comfortable with.
Herb grinders are fine for amounts up to about 7 grams. When working with larger quantities, a coffee grinder strictly for grinding marijuana, might be a better option, if time and cleanliness are a concern.
Set a coffee grinder to the coarse setting, if available, and don't grind too much. It took about 5 seconds to grind this to this. You don't want to end up with marijuana powder, because that is too fine.
The marijuana should be ground down to a point where it is about the same consistency as when you roll marijuana into a joint. See the comparison image of the relative size of ground up marijuana, it's several times larger than grains of table salt.
Place the ground marijuana in a pyrex dish or some other type of oven safe dish. Try to level the marijuana in the pyrex dish so it is roughly the same depth in all parts of the pyrex dish.
Making it relatively level and no more than about 1/2 to 3/4 inch (13-19 mm) deep, is so the marijuana gets heated at the same rate.
If you were to dump the marijuana into a pile, or if it's too deep, the material at the center will take longer to heat than the exterior, incomplete decarboxylation.
Wrap aluminum foil around the dish so it is well sealed. Some compounds in marijuana may vaporize when decarboxylating.
Keeping the marijuana as air tight as possible will help any vapor to be absorbed by the marijuana instead of escaping into the air. Regular foil is ok if that is all you have available. Heavy duty foil is best and can be reused.
Set the oven to 240°F/116°C and wait until it reaches that temperature. If necessary, use an oven thermometer for accuracy. When it reaches 240°F/116°C, put in the pyrex dish containing the marijuana in the oven.
The length of time to keep the marijuana in the oven depends on how dry it is and how it will be consumed. Marijuana that is dry will decarboxylate faster than material with a higher moisture content.
Dry meaning that it will grind easily in an herb grinder. Or if you press it between your fingers, it will break into powder if you squeeze enough.
If it is fresh or for some other reason has a high moisture content and sticks in the top section of an herb grinder or doesn't break into powder when you squeeze it, increase the heating times are required (stated below in parentheses).
If you are going to make something that will require heating the marijuana again, for example making marijuana butter, decarboxylation takes less time because the extra heating will further decarboxylate the marijuana.
From when you put the marijuana into the pre-heated oven, wait about 60 minutes (or up to 120 minutes if the marijuana had a high moisture content) with the temperature at around 240°F/116°C, then turn off the oven.
Leave the pyrex dish in the oven until it cools to room temperature and you can remove it with bare hands.
Leave it covered until you are ready to prepare it for consumption.
If you are going to make something that will require little or no more heating of the marijuana, for example making marijuana tincture, decarboxylation takes more time.
From when you put the marijuana into the pre-heated oven, wait 90 minutes (or up to 180 minutes if the marijuana had a high moisture content) with the temperature at around 240°F/116°C, then turn off the oven.
Leave the door for the oven closed and let the pyrex dish cool to room temperature. When cool, you can remove it with your bare hands. Leave it covered until you are ready to prepare it for consumption.
The decarboxylated marijuana pictured here had a high moisture content and was heated in the oven for 120 minutes, then left to cool. It might be a bit darker, medium brown, than the picture indicates, and would get darker if heated for more time.
After decarboxylation, marijuana can be made into marijuana butter or oil and prepared into a recipe that has butter or oil as an ingredient, mixed with alcohol and made into a tincture, or eaten or drunk in another way.
Marijuana with a high moisture content will lose weight when being decarboxylated. The heat will evaporate most of the water. The marijuana in the images above was 21 grams before decarboxylating, 18 grams after.
Step By Step
A) Decide how much marijuana to decarboxylate.
B) Next grind the marijuana.
C) Remember, don't grind the marijuana into powder.
D) Place the ground marijuana in a pyrex dish.
E) Level the marijuana to roughly the same depth in dish.
F) Wrap aluminum foil around dish so it is well sealed.
G) Pre-Heat oven to 240°F/116°C.
H) When heated, put dish in oven.
I) Wait until decarboxylation time is finished.
J) Turn off oven heat.
K) Leave the door for the oven closed.
L) Wait until cool.
M) Remove from oven.
List Of Materials
pyrex or other oven safe dish
optional coffee grinder
optional oven thermometer
*** oven: An oven is needed to heat and decarboxylate marijuana.
*** aluminum foil: Aluminum foil is placed over the container the marijuana is going to be decarboxylated in. Heavy duty aluminum foil is best.
*** marijuana buds: An amount of marijuana you want to decarboxylate.
*** pyrex dish: The marijuana has to be put in a pyrex dish or other oven safe dish, where it will be heated.
*** optional coffee grinder: An inexpensive coffee grinder will make quick work of grinding marijuana down.
*** optional oven thermometer: An oven thermometer will give you an accurate idea of what temperature the oven is at when it is heated.
1 --- The reason for keeping the temperature at, or a bit below, 240°F/116°C is in order to minimize the chance of cannabinoids from being degraded by the heat. There are individuals who prefer higher temperatures, so you might want to experiment.
2 --- You can vary the amount of time you heat the marijuana if you perform the procedure more than once. You might prefer the results if you heat for longer or shorter periods. Don't heat for too long or you will end up burning the marijuana.
The first few times you try decarbing, do so with dry marijuana. Moist marijuana takes longer to heat and the higher the moisture content, the longer it will have to be heated. By using dry material you will be better able to judge if moist marijuana has been heated enough.
To be able to tell, judge by the color the marijuana is after decarboxylating. Note the color of the dry decarboxylated marijuana you produce, and if you like the results aim for the same color when decarbing marijuana from the same strain with a high moisture content.
3 --- Size of pyrex or oven safe dish: A larger dish will be able to hold more material. At the research center, where these tests were conducted, a set of three pyrex dishes are always at the ready in case of situations like this.
The smallest dish is 7 x 5 inches, it can hold up to about 28 grams of marijuana buds for decarbing.
The medium sized dish is 8 x 6 inches, it can hold up to about 56 grams of marijuana buds for decarbing.
The largest dish is 9 x 7 inches, it can hold up to about 84 grams of marijuana buds for decarbing.
With the set of three pyrex dishes, up to six ounces of marijuana buds can be decarboxylated at a time. The pyrex dishes are reserved for working only with marijuana, and marijuana extracts like hash oil.
A very thorough guide on making various kinds of cannabis concentrates. Includes information on selecting and collecting material, how to make hashish, vaporizers, how to make hash oil, tinctures, capsules, edibles, topical use, and more.
The Ganja Kitchen Revolution
Lots of interesting marijuana recipes, in addition to discussing the science of cannabis with easy to follow picture examples of what the text is describing. Includes information on different marijuana strains, dose size, cannabutter and oil, food recipes, marijuana drinks, and more.
The Ganja Kitchen Revolution