This is also another cool post from someone I found on wakenedbake. This guy went deep!
It's a comment from this post -
https://wakeandbakecookbook.com/decarboxylating-cannabis-to-activate-thc/
JACKSON
May 21, 2016 at 7:21 pm
Decarbing Frank’s Gift Cannabis
I’ve been searching for a reliable way to decarboxylate medical cannabis for a while now, and there seems to be no consensus as to exactly how to do it. Different websites and forums all have a different take on the best temperature to use, how long to heat it, how to prepare it etc. My search finally led me to a British patent for a process of liquid CO2 extraction of resin from cannabis, in which they mentioned how they decarbed their samples and, most importantly, they documented the resulting lab analysis of 4 different amount of time and 3 different temperatures, and the differing results on THCa, THC, CBDa, CBD, and CBN. To me, this is a wealth of information. Here is a link to the patent:
http://www.freepatentsonline.com/7344736.html
The 3 temps are in Celsius and translate to Fahrenheit as follows: 105° C = 221° F, 120° C = 248° F, and 140° C = 284° F.
My takeaway from this long, very technical paper is the following 2 sentences:
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.
Translation: heat your cannabis in a 120° C (248° F) oven for an hour and you are good to go. Regardless of if your cannabis is high in THC or CBD this will work very well. So I did just that (sort of) and then had the cannabis analyzed at OG Analytical in Eugene, OR. Here is what I did, the lab analysis of cured Frank’s Gift bud, and the decarbed Frank’s Gift bud.
In the patent, they say it is preferable to dry the herb at a lower temp, then decarb it at a higher temp, but since I had put a pizza stone in the oven to try for a more even temp, I dried it and decarbed it at the same temp.
5/10/16 I started with 36 g total; removed 1.124 g for analytical lab testing. That left @35 g before removing stems, @ 34 g after removing .9 g of stems.
9:00 AM I put a 16″ pizza stone (9.5 lbs./4.3 Kilograms) in the oven and preheated to 250° F. I used a Farberware oven probe (laying on the pizza stone) to get an accurate temperature. It showed that it took @ 90 minutes to get up to temp.
I was aiming for a temp of 250° F, but since my oven fluctuates about 20° F, I could not achieve this. After almost 3 hours of screwing around with the oven, turning the temperature dial up and down, trying to get it to a stable temp, I gave up, and settled on a setting of 245° F.
I broke up the buds into small pieces (it was very sticky), put it on an aluminum baking sheet, and put it in the oven at 11:45AM. I left it in the oven for 20 minutes to dry completely. It was not sticky at all after drying it. I crumbled up the buds in my hand (very easy) and wound up with mostly powdered bud.
I returned the baking sheet to the oven and waited until the oven probe said 250° F, which took about 15 minutes. I left it in the oven for another hour, removed it, let it cool down a little, and weighed it. It now weighed 28 g, so it lost about 6 g of moisture (17.6%). I took out 1.15 g for the lab. Here are the lab results:
Before Decarbing
THCa = 4.8%
Δ9-THC = 0.9%
CBDa = 9.9%
CBD = 0.6%
CBN = <0.1%
After Decarbing
THCa = <0.1%
Δ9-THC = 4.8%
CBDa = <0.1%
CBD = 9.1%
CBN = 0.2%
I am thrilled with the results – all of the THCa got converted to THC, all the CBDa got converted to CBD, and very little of the THC got degraded to CBN. Not too shabby.
Next time I wouldn't mess with the oven temp. I would just set it at 245° F and leave it alone.
If you look at Table 5 in the patent, you'll see that there is quite a bit of leeway in time before the THC starts to seriously degrade into CBN, so leaving it in the oven for 1-2 hours at 250° F would not degrade very much THC (4.1% after 1 hour and 6.7% after 2 hours).
Miscellaneous notes: Franks Gift organically grown outdoors, harvested on 10/4/15, dried in 50% humidity, 70° F temp for 5 days (stems snapped at that point), then placed in 2 quart canning jars with a 62% Boveda pack for curing. It has been in the jar for 7 months.
I hope this is helpful.
Jackson
