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Decarboxylation - Turning THCA into THC by gentle heating


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This is something i have already posted in other threads here in "Strainhunters Forums". I think however it is deserving of it's own thread. So here it is.

Decarboxylation - A method of making the THC more psychoactive through controlled heating.


By Ed Rosenthal - Thursday, January 2 2003

Does marijuana have to be heated to become psychoactive?

I bought a Coldfinger to make an extract, but my problem is this: Doesn't marijuana have to be heated to become psychoactive?

My solution was to put the marijuana in the oven before putting it in the Coldfinger. But I have no idea how long I should leave it in there, let alone at what temperature. I know THC boils at 392 degrees F. But other cannabinoids, which are essential to the experience, boil off much more quickly. At what temperature can I decarboxylate the THC, while still preserving some of the cannabinoids?

Marijuana produces THCA, an acid with the carboxylic group (COOH) attached. In its acid form, THC is not very active. It is only when the carboxyl group is removed that THC becomes psychoactive. When marijuana is smoked, the THC behind the hot spot is vaporized as the hot air from the burn is drawn through the joint or pipe bowl to the unburned material. The liquid THC and other cannabinoids have a boiling point of between 180-200? C (355-392? F). Before they turn gaseous, at around 106? C (220? F), the carboxyl group is released from the molecule as carbon dioxide and water vapor.

You will be extracting the THC using low heat in the commercially made Coldfinger Extractor. (They have a very interesting online catalog at www.edenlabs.org). The THC will not reach a temperature in which decarboxylation takes place. However, if you plan to vaporize or smoke the extract decarboxylation will take place as the oil is used.

However, it is easy to make sure all the THC is decarboxylated and is at full strength before it is extracted. Although decarboxylation takes place rapidly at 106? C, it proceeds at a more gradual pace by placing the cannabis in a room with low relative humidity and room temperature. As the temperature rises, the rate of decarboxylation increases.

Cannabis can also be placed in a food dehydrator to remove the carboxyl group. Although the heat in the food dehydrator doesn't rise to 106? C, the temperature is warm enough to promote drying and the release of the water and CO2. When the marijuana is crispy and brittle you can be assured that the carboxyl group has been removed from the cannabinoids and they are ready for extraction or removal from the plant material.

Copied and pased from - http://www.cannabisc...icles/2794.html

This Article is also by Ed Rosenthal

When marijuana is harvested, the THC molecule is bound to a carboxyl group ? COOH ? that is, one atom each of carbon and hydrogen and two atoms of oxygen. With a carboxyl group attached, THC is not active.

Heating dried marijuana makes the carboxyl group convert into water (H2O) and carbon dioxide (CO2). When marijuana is smoked, the burning eliminates the carboxyl group. There are several ways to decarboxylate marijuana for use in extracts. A layer of marijuana buds or leaf can be placed in an oven at 150 degrees for 15 minutes. This is far below the boiling point of THC yet warm enough to evaporate the carboxyl group. Another method of releasing the COOH is by placing a bowl of buds in the microwave for 2 minutes. The waves will boil away the water. The boiling point of marijuana's active cannabinoids ranges from 260-392 degrees F.

The Coldfinger is made by Eden Labs, a company in Ohio that makes several models of herbal extractors, from the simple to the most sophisticated. They can be found on the internet at www.edenlabs.org.

copied and pasted from - http://cannabiscultu...icles/3037.html

How-to: Paleo's Potent Decarboxylated Cannabis Oil

How to Decarboxylate and fry cannabis oil quickly and completely

Important points:

Decarboxylate in microwave or oven (oven takes more time)

Fry the cannabis until dark brown

Eat with a meal


Butter or oil



Glass plate for microwave/oven dish for oven

Stainless Steel container or pot



Total 6 grams in my photos, which will give you anywhere from 1 to 6 doses. This is just schwag. You can use any amount, just adjust the amount of oil (to submerge cannabis) accordingly.

Decarboxylation Details:

There are carboxyl-group containing cannabinoids like cannabigerolic acid, cannabidiolic acid, which is an oxidocyclized version of cannabigerolic acid, and tetrahydrocannabinolic acid, that when they lose thier respective carboxyl group, become psychoactive.

Although all the pharmacologic literature I've read has focused on THCa, CBDa and CBGa, there are more phytocannabinoids that have a carboxyl group in them - who, after being decarboxylated - become psychoactive compounds. Nothing has shown CC's (carboxyl cannabinoids) to potentiate recreational use more then the same phytocannabinoids would as decarboxylated compounds. THIS is why you decarboxylate, to convert your THCa, CBDa, and CBGa all into non-acid forms, our beloved psychoactive compounds. So now that you know why to decarboxylate, here's how:


Microwave each set of 3 grams, for about 1 minute, 30 seconds to 2 minutes each. This is decarboxylation.

On the second batch, I re-microwaved for 1 minute to finish off.

Microwaving cannabis is safer then touching your cannabis with your hand.

If you’re decarboxylating small batches at a time you should learn how to do it in your microwave. And if it works one day, go extra time the next time. You’ll see its harder then you think to ‘burn up’ or ‘destroy’ any active cannabinoids in the microwave. Your herb will smell stronger, more pungent and crumble with ease when it’s decarboxylated - oven OR microwave method.

In the oven, you are going to want to do it for longer then 20 minutes, depending on how much bud you have, it’s degree of dryness, and your chosen temp. 325 to 350 is well known to be safe. At these temps, 25 minutes or more is more than likely necessary. If it smells more dank after the oven decarboxylation than before, and crumbles very easily, its decarboxylated.

Alternatively, you can get a food dehydrator.

You can tell when it's ready, by the strong smell (not THC escaping, but terpenes escaping) and by pinching the bud in your index and thumb finger, and trying to crush it. If the small nugs crumble, it's decarboxylated. Decarboxylation is when the THC-acid molecule looses it's COOH group, converting it from an inactive kidney cleaner, into the psychedelic THC.

How well you decarboxylate, affected by how well you can discern when the cannabis has been decarboxylated, is 50% of making this oil as potent as possible. The other 50%, is frying it until it's dark brown.

If you skip this step, or use your cannabis without it crumbling and dry, it won't be the potent oil it can be.

NOTE: Re-microwaving is safe, if you microwaved for a minute and 30 seconds and it didnt fully decarboxylate, when re-microwaving the microwave has to re-heat the glass plate youre using to hold the plant.

NOTE 2: Always decarboxylate for at least one minute! Even if it's half a gram you're doing. 2 minutes in the microwave at once, does not equal two separate one minute microwaves. The key is to heat, in the microwave, the cannabis until it smells and crumbles like it's decarboxylated.

Does Microwaving Destroy THC?

Yesterday I used the microwave to decarboxylate another batch, but this time I microwaved for 2 minutes, three separate times. This decarboxylated the bud even more! 1 minute 30 seconds to 2 minutes is safe because the glass plate doesnt get hot enough to vaporize the cannabinoids.

Even if you stop it at 2 minutes, mix up the bud on the plate, and microwave for another 2 minutes, it's safe. 2 minute microwaves in two sets does NOT equal 4 minutes in the microwave. 4 minutes will burn your cannabis and cannabinoids, but two separate 2 minute sets works to decarboxylate better than once. Yesterdays batch was stronger and I used less bud, so I know that microwaving the same cannabis twice for 2 minutes each time is safe, and reccomended.

I left the bud with small nugs as you can see on the plate below, because when I try to crush these little nugs I can get a feel for wether the bud has decarboxylated. If they crumble, they are done.

Now you have your 6 (2 sets of 3) grams of decarboxylated cannabis, it should smell stronger then before, be extra dry and crumble when you try to crumble it.

This is where you add your oil/butter of choice to the container.


Lard is not the only fat you can cook with, any fat will do, but here's why I use it (among other fats for different occasions):

Lard can be cooked with any meat, and its good to fry in. Potatoes fried in lard, thats what they call chips in the UK. If youre going to use lard for your cannabis edibles I only recommend it if you like how it tastes by itself, and you eat it the way I do in the thread. Reason being, it would taste weird in brownies, and would probably not go well on any sweets in general. Lard works for meats and broths, soups and stocks.

I eat tablespoons of cannabis infused lard with my steak meals, but thats because I've learned that saturated fat is the healthiest fat, because we've been eating it for millenia. It has large amount of saturated and monounsaturated fat. I try to keep my diet at around 65-70% fat, 25% protien and 5-10% carbs. Now that I think about it, I wouldnt eat my infused lard any other way then straight with meat, or possibly soup.

Lard is such a cheap fat, like a dollar a pound, compared to olive oil or coconut oil. Not to mention it's perfect for for frying or cooking, since it has no particles like unrefined coco/olive oil, and tastes great on potatoes and plant foods. If I want to fry some potatoes, cook some meat with bell peppers, onion, or any other vegetables, I always use lard.

If your fat is solid at room temp, like butter or lard or any other saturated fat, melt the lard or butter in the container by itself until the fat becomes a liquid. You obviously melt the butter in the container or pot over the stovetop.

Only add enough to cover the cannabis in the same container!

You can always add extra fat later, remember, but you CANT TAKE ANY OIL OUT after the cannabis is added if you put too much.

Butter bubbles when fried, so butter can help reach any bud that gets stuck on the side of the container.

Combinations of butter and other fats work too.

This is the same container, with melted lard, cannabis, and see the white thing? Thats a little bit extra (solidified at room tempurature) lard for good measure.

Sometimes you need to add a little extra oil to make sure all the cannabis is submerged.

More oil to cannabis will spread out the amount of time it takes for your body to digest the oil and recieve the cannabinoids.


That extra lard will quickly melt down into the rest of the oil.

By this time you have all of your decarboxylated cannabis inside the container, with sufficient fat to cover and submerge the cannabis.

For the frying, you only want to fry for under 5 minutes. The direct flame as you can see, heats the oil and cannabis in the container.

If you have an electric stove, use that, if you have an outdoor stove - thats even better - because there is a little bit of smoke and lots and lots of smell! This is okay and safe and you're doing it right, the smell is terpenes, not active cannabinoids.

Turn on the fans, open the windows, or if you can, do the entire frying process outside. Within about 20 minutes, the smell should dissipate anyway. But for extra safety, be ready to air out location.

Stir consistantly as it fries. It should be smelling and bubbling now. Fry like this, on a medium-high heat until dark brown. This is a fast process, about 5 minutes.

Once you think it's been fried DARK BROWN, wait an extra 30 seconds for good frying measure.

Then - careful not to burn yourself - take the container to cool outside.

When I took a look at the cannabis after being fried, I went back inside, turned the stove top on again, and fried it for an additional 2 minutes. This is because as you can see in the photographs, the cannabis was not COMPLETELY browned...

... This is of course optional, but the more you fry, the more potent the cannabis oil becomes (until you've fried it all out).

Leave it outside to cool and so the smell wont stink up your house, for about 10 minutes or so.

And there you have it! Potent, decarboxylated, properly fried cannabis oil that will knock you on your fucking ass, and then some.

You can have anything from mellow mood change(1/2 gram), regular fun trips(1-2.5 grams) or heroic doses(4 or more grams) with heroic highs using this method.

Anyone who told you that you couldn't actually have a psychedelic trip using cannabis, hasn't done this.

No matter what amount you eat, the effects last the entire day. With this method I only dose once a day, and some days I skip because the stone lingers from the day before.

Eat it with a good sized meal, preferably with protien, some fat and a small amount of carbs. It's safe to eat this infused oil with any meal including a high fat meal.

I don't separate the plant material because I eat the oil together with a meal. The plant material contains cannabinoids, you can separate it to use the oil in a recipe, and just eat the plant material separately. This does work for brownies or anything else.

Eat roughly a third to half of your meal, then take tablespoons of edibles as you desire, chase them down with water or a drink, and then finish eating.

Try to make this your 2nd meal of the day, first will work but you don't want first pass metabolism to get any cannabinoids in the oil. If you eat it as your first meal of the day, eat some food 20 minutes before you start taking the oil.

I dosed on this last night 3 grams, and saved the other 3 grams for tonight. I was so gone, 3 grams is actually a bit too much for me. I still feel the cannabinoids in my system more then 24 hours since dose time.

And this is schwag bud and prices. 3 grams comes out to about 3.50 to 4 dollars. The most prominent period of the high lasts for about 6 - 9 hours or more, depending.

I have done as low as 1/2 or a gram, and they still produce long term (6hr+) relief/benefit.

copied and pasted from - http://forum.grassci...nnabis-oil.html

Here's some links from "strain hunters" forums. The first two are from thread i posted some of this information in.

Easy Living Bud Hash Oil Tutorial by DanMacGrowsalot - http://www.strainhun...h__1#entry38854

Meet Puff the Magic Dragon ;) (Green Dragon Content) by Flial - http://www.strainhun...h__1#entry38430

Isomerization - increasing the potency of cannabis by 50% - byFuzzy - http://www.strainhunters.com/forums/topic/1693-isomerization-increasing-potency-cannabis-50/page__fromsearch__1

Peace Hunters


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Loved it very cool, so in a certain way everytime someone cooks cannabis, in butter or anything that needs heats, decarboxylate his weed without really knowing it? ^^

So Could we say it is usefull to decarboxylate the weed before smoking it too? i know it "naturally" does when the heat and smoke passes through the joint, but having the weed already ready and active could perhaps make us win a little more high or longer perhaps?

Very nice info once again thanks for sharing man ;)

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Vaporized weed is also effectively carboxylated as long as it isn't overly heated.The plant matter you have after vaping can be used in cooking or tinctures, as not all of the thc vaporizes. The plant matter left after vaping is sometimes call "gruff" or "duff".Some people might turn thier nose up at using gruff but if you run out of weed and need some medication it could be a life saver.



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yeah i guess for the vap, some people around here sold vaped weed for a while. But i mean, if i take right now 2g of the weed i have and go decarboxylate it with microwave, i understood that this was mainly done for the weed you have to eat or transform after, Will it change anything in high if i just roll it in a joint after decarboxylation?

i'm gonna try with a spliff now and tell you if i feel higher lol ^^

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Re: decarboxylated weed to smoke?

Reviving this thread because I'm experimenting with decarbing before smoking these two specific strains. They were not cured at all and the high seemed to be missing something, like it was strong in some ways and non-existent in others. The overall feeling was being high but having to stop and notice it. This is much different than being completely bakedy.

I tried the oven first. Indica bud in an oven bag. 105c or so for 45 mins. Changed it like crazy. Now it is much stronger and also hits me behind the eyes, which is just the head element this bud was missing. Turned it into sleepy weed.

The indica/sativa hybrid bud I put in the dehydrator at 130f for a few hours. It is much stronger now too. With a more fuzzy head high. Not at all sleepy. I like this bud twice as much now.

I suspect that I will end up liking the dehydrator better than the oven for this. So far so good. I just have to come down so I can try the dehydrated indica.

I will also experiment with re-hydrating to proper levels with orange peel or something.

I look forward to going back to properly cured bud, but that will have to wait until my next harvest and a long cure.

copied and pasted from - http://forum.grassci...ed-smoke-2.html

Science of smoking THC - Decaboxylation

What is it about about marijuana that makes you high? Most experienced users know that it is in fact THC (Δ9-THC or Tetrahydrocannabinol), but did you know that Cannabis in it’s basic plant form contains very little THC?

If you were to take a nice sized nug and swallow it whole (or chew it if you please), it really wouldn’t do much. This is due to the fact that rather than containing tetrahydrocannabinol, fresh Cannabis contains tetrahydrocannabinolic acid. Unfortunately, ingesting that isn’t going to do much.

When marijuana is heated, the carboxyl group is converted into water (H2O) and carbon dioxide (CO2). This occurs at 222.8°F (106°C). At this point the Cannabis can be eaten plain and will be fully absorbed by the body. When you smoke marijuana you are essentially rapidly decarboxylating the bud (and then just burning and inhaling all of the carbon in it as well). On a side note, many people advocate decarbing your herb before using it in baked goods. Apparently there’s more THC absorption, but I’m skeptical as to how much it really makes a difference.

copied and pasted from - http://420tainment.c...cience-smoking/

Review: Decarboxylation of Cannabis.


I've been researching this for a while now as ive been getting damp, crap weed and was looking some way to make it slightly more potent by drying it out - this is where i stumbled upon Decarboxylation.

I've read on a few forums about people doing this to activate inactive THC so i thought id give it a go.

(Info i used was from here: Robert A. Nelson: Hemp Husbandry ~ Cannabinoid Chemistry (Ch 6))

1st try: Microwave.

Simply droped the bud into a coffee cup and put it in the microwave at 600w for 15 seconds, took it out at 9 seconds because the stem caught fire.

Picked the burnt bit off and ground it up using my Pollen-Blitz grinder, First thing i noticed was it ground to almost dust instead of the usual tiny balls of bud.

The smoke; Harsher than usual, Really cottonmouthy, More of a instant headstone as i smoked than the Regular un-microwaved cannabis. Good high, Lasting slightly longer - Surprising result.

2nd try: Oven (At 180degrees)

Again, dropped the bud onto a piece of tin foil into the oven for 2 minutes, took it out with no burns.

The smoke: Not as harsh as the microwaved stuff, but took 12 minutes (10 mins to heat the oven) instead of 9 seconds, so personal preferance - microwave. Not as swift a come up but better then standard weed, good mellow long lasting stone.

All in all - Positive results, I'm smoking a regular joint now with untouched weed and i can certainly notice the taste difference and also lesser a stoned feeling from it.

My thoughts

If youe weed is properly cured and has very little water in it then i wouldn't decarboxylize it. You have spent a long time getting to that lovely stage, bring out the unique flavours and tastes.By carboxylizing cured weed you will mostlikely lose the terpines by heating through evaporation.In the past i have micro waved weed that i have bout due to the fact it had not been thoroughly dried.It certain was more effective at getting me high, so i would say yes it does have an effect.When smoking weed be it in a pipe or a joint the process of burning and the hot smoke/vapor being pulled through the joint will have a caboxylating effect.When making edibles decarboxylation is much more effective way of using your weed.The tree articles/posts above as far as i can see are to the most part anecdotal (the personal expiriences of the users) so I am not able to verify the validity of there statements.I guess you could try a comparrison, break some weed into two eaqual weight pieces, carboxylat one (then re-weigh to see how much water has been lost)

and then test each sample. obviously not at the same time. you should be straight (unstoned) each time you test.

I hope this helps Dust



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perfect answer man, well i tried a microwaved joint with a weed i bought that isn't particurly good or bad, didn't feel specially higher but i was doing activty's so it can mislead ^^

i'll try again, but i understand there will not be much gain :)

thanks for the complete answer ;)

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  • 2 months later...

This is a great thread! At the expo in Toronto a couple days ago there was a doctor making an almost entire speech about THCa versus THC and he was talking a lot about how THCa doesn't have any psychoactive effects. I'm not sure who made this point up there but I agree about the taste. I find fresher buds ( I guess I really mean more moisture left) will smoke smoother and have a better taste but, on the other hand, I find that really dry weed that breaks up into dust packs more of a punch when it come down to the high. I never really thought about any of this until reading this thread. That could be why I like it so much!


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  • 4 months later...

Hi all thanks for you comments :)

Dave M, i was listening to a coast to coast show about medical bennefit of cannabis , one thing that was interesting was that some paitents are using "raw" cannabis ie. not dried atall to get the effedts of the other cannabiniods and not get high.

For those who want to get high the proper drying and decarboxilation prior to making tinture etc is the way to go.

Nazreth 225 i'm glad to see you enjoying the forums :)

Peace hunters


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Heh :) nice comment Fim

I know what you mean about slow drying always the best option.

I have also done micro and sometimes if it aint been flushed properly (I'm talking about weed i have bought) those salts can make your bud spark.

so yeah nice and slow is the way to go. :D

Those muffins sound good



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