Materials:

5 gallons of bleach (8.25% sodium hypochlorite)
500ml acetone
sodium bicarbonate
distilled water (300ml)
Magnesium sulfate 100g

Time: 8hrs
Yield: Loads (I didn't weigh this extraction.)

A large amount of trimmings were set out to dry in a sack, and dehydrated near a heater for several days.

..meanwhile..

400ml methylene trichloride was prepared in situ, and distilled twice for purity in a hot water bath, and dried over MgSO4. An unweighed mass of very dry cannabis extract was pulverized to a powder and poured into a 1000ml round bottom flask. To the flask 400ml chloroform is added. The solvent is setup for reflux in a hot water bath for 1 hour. 

The contents of the flask are poured through a funnel, and the filtrate washed once with a sodium bicarbonate solution, and twice with water. The chloroform was dried over dehydrated magnesium sulfate,filtered, and excess chloroform was distilled off.

The plant material was again added to the freshly distilled chloroform, and the above process repeated to be sure all THC is liberated. The chloroform remaining after distillation was evaporated and a relatively pure clear-brown viscous THC oil was recovered.

The whole process was very quick, much safer (and cheaper) than butane gas, and like the title says: does not leave a residue behind. THC decomposes in UV light, be wary of that.

Any questions will be discussed here, I'll be doing this several times throughout the week for those of you with questions.

nice write up ♡

A simple dessicator was made by microwaving epsom salts in a baking dish, moisture was whiped off. A screen is fitted inside the dish, cannabis leaves are piled on top of the screen, and the container sealed shut and placed in a freezer.

The dried cannabis was ground to a powder, placed in a 1L beaker, and covered with chloroform. Chloroform was heated to 50c for 20 minutes, and the slop was poured through a fritted glass funnel. The chloroform was purged and replaced by methanol, heated and stirred vigorously for 10 minutes, and set in a freezer over night.

The methanol was poured through a fritted glass filter, and the filtrate was washed with basic water quickly, 2 times, then once with distilled water to remove basic residue.

The methanol was purged, and the remaining oil decarboxylated with cyclohexanol/spearmint oil. The cyclohexanol solution was purged, and the oil was again washed with basic and distilled water. The oil was dehydrated, and heated in an oven until fluid. The fluid was loaded into dram vials via syringe.

Due to the difficulty of keeping the extraction 100% dry I added in purification steps to remove water soluble gunk, a highly potent extract can be had immediately following the chloroform purge. Methanol is rather poisonous and may be substituted with isopropropyl alcohol. Chloroform rapidly extracts the highest amount of cannabis oils, rather quickly. A soxhlet will excel for the initial chloroform extraction, and reduces fumes. A soxhlet however, would take much more time than necessary to perform this extraction.

Very interesting thanks for sharing. What kind of product is yielded? E.g shatter, budder, oil, crystals etc.? Do you have any pictures of the final product? How is the taste? Are the non canabinoid terpenes conserved in this method?

Why the spearmint oil? I thought that a,b unsaturated ketone catalyzed decarboxylation is done specifically on amino acid substrates. That decarboxylation works through an intermediate imine, but there is no amino group on cannbinoids to form an imine with the ketone. Furthermore, how do you effectively separate the spearmint oil from the resin after the decarboxylation is finished?

Anyway, isn't THCA adequately decarboxylated simply by heating?

I pre-mixed it with the catalyst for other uses prior to adopting acetylphenone. Cyclohexanol is a high boiling solvent that will work just fine for a decarb. The rotovap and a strong vacuum should remove most of the spearmint oil.

Due to a long reflux in chloroform the final product is black oil (amber when stretched out). I believe terpenes are in thr final product. The taste is almost entirely flavorless. I was debating on a conversion/isomerization with ZnCl2 but the final product is VERY potent. Next time I'll just extract quickly with chloro.
.

out of curiosity, habe you ever tried the thing in otto snow's book cocaine and thc where he sonicates 4g of 35%w/w THC crude extoract (extrracted with hexane) in some alcoholic MeOH for a few hoursm, then basifies it with a bit fo naoh and re-extracts with hexane for like 2.75g of 71% thc w/w extract?

i should find the page...always intrigued ,e but never tried

I haven't, chloroform is reported to pull 80-90% thc on the first run, and it has a much higher vapor pressure. I could have just ran it through a column with shredded leaf packed inside for a more transparent product. A sand chromatography column is ace for cannabis extractions

Next time I extract, what I'll probably do is hook up one of these:

-to a round bottom flask, pack in some leaf, and run chloroform through it in short bursts. Think BHO chloroform style. I can simply just clip the flask onto the rotovap and off I go. Pouring it onto a baking dish would also work.

Regards, 1ce

Just poking around about - Sexy column, mate!

As much as I like the solvent approach for other things science
I prefer Rosin tech and Distillation techniques for oil-making.

Still good ideas - Refine further & show pls

If the product is flavorless and chloroform pulls 80-90% THC, I don't believe you have significant terpene content in your product. Concentrates with significant terpene content, in my experience, usually have a very strong odor and tend to be less viscous and lighter in color than concentrates from the same starting material produced the same way. I know of a few extractors who actually use purified terpenes, such as limonene, as solvents to hold near pure THC in a stable, pourable solution.

I'd still be inclined to try chloroform for cannabis extractions, though I wonder whether one could get adequate terpene content if some of the purification steps were abandoned.