CANNABIS SATIVA SEU INDICA: INDIAN HEMP. Feb 9th 1895

[dizzlekush]

Here's a relevant study: (underlines added)

Direct NMR analysis of cannabis water extracts and tinctures and semi-quantitative data on D9-THC and D9-THC-acid
M. Politi, W. Peschel, N. Wilson, M. Zloh, J.M. Prieto a, M. Heinrich

A novel approach based on NMR spectroscopy, 1H NMR experiments with suppression of the ethanol and water signals and diffusion-edited 1H NMR (1D DOSY), was developed and successfully applied for the fast and direct analysis of tinctures. Relative amounts of D9-THC and D9-THC-acid in the extracts analyzed vary depending on the temperature (extraction with hot and cold water) and the polarity of the solvent used for the extraction (tinctures with different ethanol strength). To the best of our knowledge, this is the first time that the polarity of the solvent used for the extraction is described as a factor that can affect the relative quantity of D9-THC respect to other cannabinoids in the extract. Fraction CS20_c from the 20% tincture fulfills the demand for cannabis extracts low in D9-THC still containing other cannabinoids of medicinal interest. Further studies to maximize the yield of this promising mixture of cannabis products are ongoing. As for the aqueous extracts, this approach revealed the non-negligible presence of D9-THC and D9-THC-acid in infusions of cannabis which may, at least in part, explain the recreational and medicinal uses of this particular preparation. In the emerging metabolomic era, it is essential to monitor how manufacturing procedures affect the final content of natural products in herbal medicines.
http://www.google.com/url?sa=t&rct=...Y1KQ1t1zDRrO6IIjg&sig2=TB80mQVtGuFlBmd074sIlQ (PDF)

If levels of ethanol are found to be too intoxicating, excess ethanol can be evaporated from solution at ~175F

 

[G.O. Joe]

In the organic fraction from the hot water extract (CShw_c), the content of D9-THC is 1.52 times that of D9-THC-acid while in the organic fraction from the cold water extract (CScw_c) the relative amount of D9-THC is reduced to 0.09 times that of D9-THC-acid. The higher amount of D9-THC in the hot water extract is due to the known decarboxylation of D9-THC-acid into D9-THC that occurs approaching 103C (Segelman and Sofia, 1973). Based on the solubility of D9-THC in water (2.8 mg/l), from 25 ml of water a maximum of 0.07 mg of D9-THC can be expected. However, from 25 ml of the hot water extract 13 mg of a mixture containing more than 50% of D9-THC was obtained. This result indicates that the use of high temperature or the presence of other compounds from cannabis favour the extraction and solubilisation of D9-THC in water...

Five grams of dried CS were extracted with 100 ml hot water (heating and boiling for 3 min) and after filtration approximately 50 ml of this decoction, labelled CShw, were recovered. Another 5 g sample of CS was extracted with 100 ml cold water (overnight under agitation, room temperature) and after filtration almost 50 ml of this extract labelled CScw were recovered. 25 ml of both water extracts were extracted with 5 ml of n-hexane (3 times) and these organic fractions, labelled CShw_c and CScw_c, were dried in the rotavap to give 13 mg and 5 mg, respectively.

 

[dizzlekush]

Reorganized some of my PDF's and came across this misplaced one:

Cannabis tea revisited: A systematic evaluation of the cannabinoid composition of cannabis tea
Arno Hazekamp, Krishna Bastola, Hassan Rashidi, Johan Bender, Rob Verpoorte

Here's an excerpt from the conclusion:

...By performing a series of experiments, we systematically discovered the effect of different parameters on the cannabi- noid composition of medicinal cannabis tea. The study of pure standards in boiling water provided detailed insight into the behaviour of THC and THCA during the tea preparation pro- cess. Relatively, more THCA was solubilized in boiling water than THC, which probably can be understood by the relatively higher water solubility of THCA compared to THC (Hazekamp and Verpoorte, 2006). Interestingly, although the amount of THC in the used amount of cannabis (1 g) is potentially very high (about 174 mg, as sum of THC and THCA), the whole volume of standard tea contains only a fraction of this (about 10 mg THC per liter) in the water phase. This relatively low concentration is probably the result of saturation of the water phase with THC, in combination with a moderate conversion of THCA into THC, as was also suggested by the experiments performed with pure standards.
In case storage of cannabis tea is required, the addition of a solubilizer was found stabilize the THC and THCA levels of the preparation for a period of at least 5 days. Although addition of the cyclodextrin RAMEB clearly improved the stability of cannabis tea, its oral use has not yet been fully validated and its common use in medicinal preparations might still take several years to be established. However, the addition of coffee creamer can be an easy and safe alternative for medicinal consumers
of cannabis tea to stabilize their preparation during short-term storage.
Finally, some attention should be given to the unique composition of cannabis tea, compared to other forms of admin- istration, where heating of the material is typically performed at much higher temperatures (e.g. smoking, vaporizing or bak- ing), resulting in a virtual complete conversion of acidic into neutral cannabinoids. This is the reason that, during studies into the medicinal effects of cannabis preparations, the atten- tion is commonly focussed on THC alone. However, in the cannabis tea studied, a significant proportion of THCA was found. The recently described immuno-modulating properties of THCA (Verhoeckx et al., 2006) may contribute to the effects that certain groups of medical users claim after consumption of cannabis tea. Furthermore, a variety of other acidic cannabi- noids were found by HPLC analysis, such as cannabigerolic acid (CBGA) and tetrahydrocannabivarinic acid (THVA). Although the biological activities of these compounds have hardly been explored, their presence makes cannabis tea a unique adminis- tration form that should not be considered as simply a vehicle for THC...

It also mentions several relevant studies in the references such as:

Hemp tea versus hemp milk: subjective effects and elimination studies of THC and its main metabolite

High-performance liquid chromato- graphic determination of delta9-tetrahydrocannabinol and the corresponding acid in hemp containing foods with special regard to the fluorescent prop- erties of delta9-tetrahydrocannabinol

Unheated Cannabis sativa extracts and its major compound THC-acid have potential immuno-modulating properties not mediated by CB1 and CB2 receptor coupled pathways