Decarboxylation : How much heat and time ?

I have done extensive archive searches in this forum to see if I could find out the ideal and optimal oven temperature setting and length of time in the oven, that will consistently yield the highest rate of THCA to TCH conversion, without overdoing it and having significant amounts of that precious THC degrading into CBD.

In reading the sheer variety of opinions on this subject, I was reminded of a quote attributed to Bob Dylan, in which he reportedly said " One thing I learned in college, is that a lot of people go to college."

I am also reminded of the words to an old country song by Don Williams, which includes the phrase " A panel of experts can shout all night, and never figure out which one is right."

Cutting to the chase, I found in the archives no less than TEN different recommended oven temperatures and oven decarb times, and I would like to list them all together here, so y'all can look 'em over and maybe help narrow down to a most favored decarb oven time and over temperature, which I can then carve in stone and use for the rest of all time.

Here are the various opinions that I found during my archive research in this cooking cannabis forum, regarding just how long to bake dry herb in the oven, and what temperature to set the oven.

100 degrees for 20 minutes
100 degrees for 60 minutes
150 degrees for 15 minutes
160 degrees for 5 minutes
160 degrees for 10 minutes
220 degrees for 20 minutes
275 degrees for 5 minutes
280 degrees for 20 minutes
300 degrees for 20 minutes
Microwave for 2 minutes

I wish I knew how to run a poll in my post here, but since I don't I sure would be grateful if as many of you canna-chefs as possible could look over the above listed oven times and temperatures, and help as best you can to identify the most THC-productive combination of time and temperature, selected from the above list I collated from past discussions in this forum on the subject, going back over a few years of ICMag forum archives.


Additionally I saw and noted in these forums a statement made that TCH "melts" at 260 degrees, and "boils" at 392 degrees. Can I take this to mean that it would be unwise to decarb weed at any temperature above 260 degrees ?

The subject of decarbing becomes more perplexing the more I read opinions on the best way to go about it, so a summary of sorts would be much appreciated by this aspiring canna-coconut oil alchemist.

Hey Swamp Thang,

I've been working on this for a long time. I've used temps from 300 down to 200 degrees F.

I've had a lot of success at a verified temp of 245 F. I got a cheap oven temp gauge that sits in the oven during on times to make sure that the temp is correct. It will take some time to figure out the true temps of your oven. I set my oven at 225 F and it actually heats up to 245 in about 10-15 minutes.

I place my ground dry material or cut up fresh plant in a ceramic bowl and cover with aluminum foil and I then put a rubber band on it to make sure that it is sealed. Or you could just wrap the whole bowl in foil. I then place the bowl on a burn proof aluminum cookie sheet. I place the bowl in the oven then I turn it on. I don't wait for it to preheat.

I cook it for 60 minutes. I let it cool. I then add soy lecithin and coconut oil. I mix then I cook it again for another 60 minutes. When cooled I strain it. Sometimes I cook with it or I just drink it!

I prefer the high / stone found with edible oils. I also prefer the length of the high.

My advice would be to get your oven calibrated, and then just experiment with temps.

RF

Scottish Research I thank you for this very helpful reply. It didn't occur to me that the oven might be a good deal hotter than the temperature I set on the dial, so I think I'll copy your idea of placing a thermometer in the oven to get an accurate reading while de-carbing.

Your oven time of 60 minutes is among the longer durations I have seen used for the decarb process, but if you are getting a decent high after that length of oven time, clearly the THC has not degraded into CBD, even after a whole hour at 245 degrees.

I have not been very impressed with the high I obtained from my decarb process using coconut oil, which has thus far been ten minutes at 180 degrees for the de-carb, followed by an 8-hour simmer in a crock pot for a slow extraction, using a water and coconut oil combination, with the water layer discarded after cooling in the fridge, as recommend by Terpene in this forum.

Since I started out with decent weed that did the job when smoked, I assumed that the relative drop in potency of my edible oil was due to a fundamental flaw in my decarb process. I am about ready to try making another batch, so I will try a longer oven time of up to 45 minutes to accomplish that elusive decarb, using a higher temperature close to the 245 degrees that has worked with your experiments.

Once again I thank you for helping clear up the confusion I have had on this subject. If I can just refine my canna-oil production process to get consistently potent oil, I plant to quit smoking entirely to save my lungs, and just bake cookies that I can innocently snack on in public without drawing any attention. The stealth aspect of edibles really appeals to me a lot, so my mad experiments will continue until I hit pay-dirt, and arrive at the perfect decarb and extraction process.

Swamp Thang said:

Scottish Research I thank you for this very helpful reply. It didn't occur to me that the oven might be a good deal hotter than the temperature I set on the dial, so I think I'll copy your idea of placing a thermometer in the oven to get an accurate reading while de-carbing.

Your oven time of 60 minutes is among the longer durations I have seen used for the decarb process, but if you are getting a decent high after that length of oven time, clearly the THC has not degraded into CBD, even after a whole hour at 245 degrees.

I have not been very impressed with the high I obtained from my decarb process using coconut oil, which has thus far been ten minutes at 180 degrees for the de-carb, followed by an 8-hour simmer in a crock pot for a slow extraction, using a water and coconut oil combination, with the water layer discarded after cooling in the fridge, as recommend by Terpene in this forum.

Since I started out with decent weed that did the job when smoked, I assumed that the relative drop in potency of my edible oil was due to a fundamental flaw in my decarb process. I am about ready to try making another batch, so I will try a longer oven time of up to 45 minutes to accomplish that elusive decarb, using a higher temperature close to the 245 degrees that has worked with your experiments.

Once again I thank you for helping clear up the confusion I have had on this subject. If I can just refine my canna-oil production process to get consistently potent oil, I plant to quit smoking entirely to save my lungs, and just bake cookies that I can innocently snack on in public without drawing any attention. The stealth aspect of edibles really appeals to me a lot, so my mad experiments will continue until I hit pay-dirt, and arrive at the perfect decarb and extraction process.

Click to expand...

I can't speak for plant material but I decarb BHO for use in cooking, and I use coconut oil.

For my own purposes I simply wait until it's done

With the coconut oil and BHO in the oven at 230F it'll start to produce TONS of tiny bubbles. That's the CO2 being released.

When the bubbles stop, it's done. Usually it takes about 2 hours for a reasonable amount. I decarbed 400g of BHO and it took like 3-4 hours to finish.

You can see the bubbling in this sort video. View in fullscreen at high-res.
When this bubbling stops, my oil is done
[youtubeif]6IA-eBqqJls[/youtubeif]

If anything with THC is in my oven the temps never exceed 290 F . Drying and decarboxing is something I would rather do on the lower end at around 100 f max .. I dry it slow and would rather error on the low temp then a high temp that could burn the herb if I am not on top of watching this process . I use no timer and once my material is crispy all is well , too many variables with starting material for me to use a timed regimen.

Why do I bake at 290 - Take a look at Greywolfs notes over at Skunkpharm , he has shown us in diagrams exactly where it begins to degrade due to heat and if memory seves me well is just a little over 300 F . Joe stated this too me years ago and I admit it made a huge difference in my finished products

xxPeacePipexx said:

If anything with THC is in my oven the temps never exceed 290 F . Drying and decarboxing is something I would rather do on the lower end at around 100 f max .. I dry it slow and would rather error on the low temp then a high temp that could burn the herb if I am not on top of watching this process . I use no timer and once my material is crispy all is well , too many variables with starting material for me to use a timed regimen.

Why do I bake at 290 - Take a look at Greywolfs notes over at Skunkpharm , he has shown us in diagrams exactly where it begins to degrade due to heat and if memory seves me well is just a little over 300 F . Joe stated this too me years ago and I admit it made a huge difference in my finished products

Click to expand...

Doesn't THC begin to vapourize at 250F ?

I sure appreciate the input here fellas. I 'll checking back here often, and taking notes. My philosophy thus far has been similar to that described by Peace Pipe, in that I have kept my temperatures at the low end of the oven's capabilities, for fear of burning up the TCH, or having it convert to sedative CBD.

For my next batch I might try a low temperature in the 180 degree region, with a longer time in the oven that I've used so far, but then also run another batch alongside the first one, using the same weed for potency comparisons, but this time with higher temperatures carefully kept BELOW say 220 degrees, and a similar 20 minute run in the oven, since 20 minutes oven time for herb does appear to be about an average duration of decarb time.

BigJohnny said:

Doesn't THC begin to vapourize at 250F ?

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I do believe your right but that is a reference of material temp and vaporization . Baked goods rarely hit this temp internally when baked at just under 300 f . I dry/decarbox my material at an average temp of 100 f.. I cant really say much about vaporizing as I dont like to vap weed

xxPeacePipexx said:

I do believe your right but that is a reference of material temp and vaporization . Baked goods rarely hit this temp internally when baked at just under 300 f . I dry/decarbox my material at an average temp of 100 f.. I cant really say much about vaporizing as I dont like to vap weed

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Vaporizing your bud is one thing, but I'm talking generally. @ 250F THC negins to vapourize, so anything above that will definitely be detrimental to the amount of THC.

Things in the oven may not get that hot internally, but it can still have an effect.

I made some cookies lastnight, had to bake them at 375F.

One of two things happened.....

My butter suks (most likely reason right now)
And/Or
I lost a bunch of THC due to heat.

I think I fucked up my butter though.

Check out this old thread where I experimented with a decarboxylation technique that requires "two heatings" at specific temp and time....which is based on information I gleaned from a patent.

https://www.icmag.com/ic/showthread.php?t=203923

The specific method I used:

1. 55 grams of flowers were placed in 1/2 gallon Ball- Mason canning jars--(which are designed to withstand 280 plus degrees).
2. Digital thermometer probe placed inside jar but not touching glass.
3. Pre-heat oven to 240 degrees
4. First heating (to dry all material)...I waited until the thermometer registered 220 degrees and reduced the oven to 220 degreds (it took about 45 minutes) and continued to "cook" for 15 minutes, and peaked at 224 degrees.
5. Second heating (to convert acids to neutral form)...I covered the jar (phew, no more aromatics) and continued at 220 degrees for 90 minutes....for flowers high in CBN, the patent suggests 240 degrees at 60 minutes.
6. Cooled for 1 hour...net weight was 45 grams.


Now from that patent, "Extraction of pharmaceutically active components from plant materials":

http://www.freepatentsonline.com/7344736.pdf

"Approximately 4 kg of milled BRM (either THCA or CBDA) to be decarboxylated was initially heated to 105° C. and held at this temperature for about 15 minutes to evaporate off any retained water and to allow uniform heating of the BRM. The batch was then further heated to 145° C. and held at this temperature for 45 minutes to allow decarboxylation to be completed to greater than 95% efficiency."

And regarding THC/CBD herb--btw, "Chemovar" means "cannabis plant material".

"Therefore laboratory studies demonstrate the optimum conditions for the decarboxylation of:

Chemovar producing primarily CBD is 1 hour at 120° C. or 0.5 hour at 140° C.
Chemovar producing primarily THC to minimise CBN formation, is 1 to 2 hours at 105° C. or 1 hour at 120° C."


Tables from that patent that show different THC/CBN rates at different temps--



IMHO, there is a sweet spot (temp & time) that can be obtainable, depending if the herb is high in THC or CBN.

Hope this helps...

xxPeacePipexx said:

Why do I bake at 290 - Take a look at Greywolfs notes over at Skunkpharm , he has shown us in diagrams exactly where it begins to degrade due to heat and if memory seves me well is just a little over 300 F . Joe stated this too me years ago and I admit it made a huge difference in my finished products

Click to expand...

In actuality, if you track the temps of typical baked goods in the usually recommended 350* baking environment you will find that the food rarely exceeds the temperature of boiling water. Until you bake off all the moisture that's where the heat will max out, hence the advisability of pre-decarbing your material before cooking - especially with baking/heating times of less than 30min.

Eclipse 420 I am very grateful for your providing this detailed, scientifically derived information on this subject.

This is just the sort of definitive study that I can pore over, and use to formulate a plan for success with my decarb experiments. I am cutting and pasting this precious information now, for future reference.

Once again I sure do appreciate this wealth of data, and I really do now feel that with this information, I can impart a little more method to my mad dabbling in this dark art he he.

Swamp, go to the patent link...both pdf & text versions available.

BTW, from what I can see, the relationship between temp and time is linear...in other words, plot the published data points on a graph and you will see the relationship between temp and time is almost a straight line. Example suppose your temp is only 210...not 220, the graph will indicate the appropriate "time" for 210 degrees.

I no longer "extract" so--it has a few years since I decarbed...but it is something I would consider should I ever grow a crop of substandard "weed"....decarb it first then have it blown.

That patent document does make for some daunting reading, Eclipse420, with the array of research data presented, but I can see that Table 4, reproduced from that paper in your post above, does indicate that the final TCH content produced by heating the buds reaches a maximum value only at a temperature of 105 degrees Celsius (216 degrees Fahrenheit), and after 2 hours of heating at that constant temperature.

Despite seeing these figures, I am still a bit hesitant to leave my buds in the oven for as long as 2 hours, for fear of converting too much THC to CBD, so I will try decarbing a small test batch of weed at 220 degrees ( my oven's closest setting to the optimum temperature of 216 degrees Celsius) for a duration of 90 minutes, before using it to make up some canna-coconut oil in my crock pot in the usual way, to see how the results compare to my previous efforts.

Once again I thank you for helping clear the fog so that my efforts can become a bit more focused towards replicating, or at least approximating laboratory-established findings regarding the most effective procedure that will maximize the THC content of my canna coconut oil.

Exactly....do a test batch and see what you get. Maybe a series of "tests"....like 5-10 grams per mason and start pulling them at specific intervals (I did 10 minutes a part)--then compare. I was amazed and surprised of the difference that 10 minutes made...each batch was similar but quite different.

The patent is a tough read...but focus on the "decarb" discussion--super critical CO2 processing is interesting, but of no value for decarbing. It jumps around a few spots (yellow highlighter) and it took me about a dozen reads before I actually understood what "I know"....lol. So, smoke a fatty and don't be bashful if you find yourself reading the same paragraph over and over.

Also...the lower the temp, the longer time duration---the higher the temp, the shorter time duration. Like I said, it is linear. Same...same.

Wow this is really interesting.

Thanks for the info.

I used this from SkunkPharm. Their website has a very well done explanation of a bullet proof method to decarb extracts. I have never decarbed flowers before, I have never had a need to. But I imagine the same graph still applies. It will just be harder to know if/when everything is done decarbing.

Excellent info, thanks everyone.

hot fast decarb seems where it is at.....

I do the crock pot method half the time with water....6+hours...

I have also done the quick heat butter only style watching for the bubbles....Seemed to be similar potency...but I know I am missing some as I have had some variation in the batches, dispite using the same material. Time being the difference...tried 8 hours....tried 4 hours...tried with water, without...

Seems easier to extract then decarb imho...just costs more.