Hey everyone! I took a hiatus after I got sort of burned at another forum. I think it's probably because I stepped on some regular users toes, but I'm really glad to be here and on a few other forums at the same time, I plan on learning along with everyone and sharing what I find interesting.

Luppz, no your reheating won't burn any of the existing cannabinoids. Don't pass the flash point of the oil you're using. Good luck!

Fellow, where did you think I said to decarb at 300F? My decarb method here is microwaving, but I think that anywhere from 250 to 275 is a safe temperature to decarboxylate with an oven bag or a lid in the oven.


Extraction of pharmaceutically active components from plant materials

Decarbing is best at 105c-145c depending on the size of the batch, and the ratio of carboxyl cannabinoids (THCa:CBDa). CBD is more resistant to decarboxylation, and with high THC containing cannabis there is a third criterion, which is THC's degradation into CBN.

There is a nice graph of times and temperatures and the change in carboxyl vs. free cannabinoid contenton my harddrive, I'll upload it tomorrow.

Laboratory Studies-decarboxylation

Portions of milled dried plant material were subjected to heat (approximately 0.25 g with particle size 1â??2 mm). A pilot scale experimental system was set up, with the objective of determining parameters for the optimal conversion of THCA or CBDA into THC and CBD respectively, with concomitant minimal loss of these ensuing compounds into their thermal degradation products, in the case of THC the formation of CBN.

Brief Description of Materials and Methods:

Portions (0.25 g) of milled (approximately 1â??2 mm particle size) of both THCA and CBDA herbal materials were placed in 20-ml glass headspace vials and the vials sealed tightly with crimp capped Teflon-faced butyl rubber seals. Sealed vials were heated at one of three temperatures, for periods of up to 4 hrs as follows:

105° C., 120° C., 140° C. for 0.5, 1.0, 2.0 and 4.0 hours.

The heating was performed in an oven with forced air circulation. Oven conditions were shown to be accurate to within 0.5â??1.0 degree at the three temperatures used.

After the heating process was complete representative samples of the decarboxylated herb were assayed using HPLC, GC and TLC techniques. Standards of THC, CBD and CBN were include in the HPLC and GC sequences.

Results and Discussions:

HPLC analysis of the solvent extracts was able to demonstrate the disappearance of either CBDA or THCA as a function of time at the two lower temperatures. At 140° C., the earliest time point samples at 0.5 hour contained only very modest levels of a peak eluting at the retention times of CBDA or THCA.

Tables 3 and 4 present HPLC data quantifying the conversion of CBDA or THCA into the free compounds; also presented is data showing the content of CBD or THC and the ratio of CBD/CBDA+CBD or THC/THCA+THC. The conversion of the carboxylic acid forms to the corresponding decarboxylated form can be monitored by comparing the decarboxylated/decarboxylated plus un-decarboxylated ratio with the absolute content of the decarboxylated compounds. Thus, when the ratio reaches a maximum value (>0.95), the earliest time/temperature point at which the content of THC or CBD is also maximal, should be optimal for the conversion process.

Thus, for CBD containing herb, 1 hour at 120° C. or 0.5 hour at 140° C., was appropriate.

This is confirmed by examination of the TLC chromatogram for the solvent extracts, CBDA is absent after 1 hour at 120° C. or at any time point at 140° C.

For THC there is a third criterion, formation of CBN, where it is desirable to minimise the formation of this compound during the thermal decarboxylation process. Table 5 provides Gas Chromatography (GC) data where a CBN/THC ratio can be derived. Taken into consideration, alongside the THC/THCA+THC ratio and the maximum THC content, minimal CBN formation occurs after 0.5 or 1.0 hour at 120° C. At 140° C., even 0.5 hour gives a higher content of CBN than either of the two lower time/temperature points.

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.
Thin layer chromatography reveals that virtually all of the THCA has disappeared after 4 hours at 105° C. and after 1 hour at 120° C. No THCA is visible at any time point when the herb is heated at 140° C. A small amount of residual staining at this retention value on TLC and the presence at low levels of a peak coincident with THCA on HPLC analysis may indicate the presence of a minor cannabinoid rather than residual THCA.
Unfortunately the tables come out scrambled here, but there is absolutely no single best temperature for decarboxylation. Take a look at the tables for decarboxylation degree of THCa containing vs. CBDa containing cannabis. You can however estimate, and use oven bags or boiling bags (boiling in a sealed bag at 105c is a safe decarboxylation method) or even just vaporizing are efficient ways of decarboxylating. Only trace amounts vaporize at around 285F, and this is with airflow, which isnt the same as without. Anyway, I'll post up the graphs tomorrow, the wife is calling.



Paleo