For those of us who never quite got over the loss when fine-quality hash oil disappeared from the market, and for cannabis connoisseurs of all ages everywhere, it would be my honor to write up what has to be the easiest, highest-yielding and most selective cannabis oil extraction method available to date.

This method has its basis in a fascinating industrial extraction method known as Supercritical Fluid Extraction. It uses totally over-the-counter butane gas (8 oz can, camping supply store, ~US$4.50) as the extraction solvent, and requires nothing even remotely suspicious or difficult to purchase. The only other thing needed is about $2.00 worth of PVC pipe: a section 1.5 (one and a half) feet long and 1 & 3/4" diameter (outer diameter I believe), and two end caps. Threaded PVC is not necessary.

For reasons not yet clear to those of us investigating these things "unofficially," butane (and perhaps other gas/solvents with similar ultra-low-boiling properties) selectively solvate the desirable fraction(s) of cannabis oils, pulling out only a beautiful amber "honey oil" and leaving the undesirable vegetative oils, waxes, chlorophyll, etc. behind in the plant matter. Even unsmokable shade leaves produce a wonderfully clean and potent gold oil with this method. I have every reason to suspect that this would work splendidly to extract a super-strong and tasty oil from gross, unpalatable "schwag" commercial pot too, and of course, the better grade of herb you put it in, the better the resulting oil.

Note that the amount of honey oil resulting is very low. Cannabis leaf and bud varies in THC content from 0.5% to over 10% for extremely high potency bud, with the average for normal quality material in the 1-3% range. With a perfect extraction (this method will not approach 100%), that would mean less than a gram of oil from each ounce of leaf and between 1 and 3 grams of oil from each ounce of high-potency bud. The primary use for this technique is to render leaf into a form more appropriate for medical use by removing other tars and ash-producing material from the psychoactive principals.

METHOD:

1. In one of the PVC end caps, drill a single small hole in the center. This hole should be correctly sized to snugly receive the little outlet nozzle of your butane can.
   
2. In the other end cap, drill a group of 5 or 6 small holes clustered in the center (like a pepper shaker).
   
3. After putting a piece of paper towel or coffee filter inside it for filtration, put the end cap with several holes on one end of the pipe. Push it on there real tight. This is the bottom.
   
4. Fill the pipe up with plant matter that has been pulverized into a coarse powder. You want it filled, but not packed down. (Full pipe estimated at 1.5 oz capacity, but this is a guess. I did not weigh it.)
   
5. Place the top end cap on the pipe. Again, push it on as securely as you can by hand.
   
6. Find a location outdoors with a decent breeze. You want these butane fumes to be quickly carried away. Seriously.
   
   1. Mount the pipe (single hole-side up) over a vessel that can hold 300 mL+. Beakers are perfect. A lab stand and clamp are ideal for the mounting, but a regular shop clamp or anything that can hold it sturdily is fine. (Avoid metal if you can, to reduce the chance of sparks.) Position the bottom end of the pipe immediately over (1-2") the receiving vessel to eliminate splatter loss.
7. Turn the butane gas can upside down and dispense the gas into the pipe via the single top hole. A whole 8-oz can takes about 10-12 seconds to evacuate. Be brave, swift, and careful. A spark at this moment would spell disaster since you have basically created an incendiary explosive device that is leaking.
   
8. When you've exhausted the can into the pipe, back off to a nice distance and let it do its thing.
   

The butane moves down the pipe, extracting the cannabis as it goes. When it gets to the bottom (~30 seconds after dispensing), it begins to drain into the receiving vessel. Notice the pale, glowing yellow-green-gold hue of the extract. It is obvious no chlorophyll was pulled out of the herb.

Over approximately five to eight minutes, the butane extract will finish draining from the pipe to the receiving vessel. Maintain caution with the pipe, however, since there is a lot of residual butane still evaporating from within the pipe (notice the stream of fumes coming from the top hole). When it slows down to a drop every few seconds, you can tap on the top hole with your finger and it will help push the last of the liquid butane out (or one can gently blow into the top hole to do the same thing). Remember, NO SMOKING, unless you wish to immolate yourself in grand fashion.

Being very low-boiling and volatile, the collected butane will likely begin boiling at ambient temperature. The receiving vessel will gradually frost up as the butane cools it down, slowing down its rate of evaporation, but you can speed this up again simply by holding it in your hands. A better way is to set it in a saucepan containing a little bit of warm water. Watch the butane start bubbling madly with the increase in temperature and marvel at its low boiling point. Again, be doing this outdoors with a nice breeze! It takes about 20 minutes or so to allow the butane to evaporate, or quicker if you help it along. You are left with a deep amber, almost orange oil of amazing purity.

The best way to collect and store the oil is probably to let all of the butane evaporate off and then redissolve the oil in some anhydrous or high-% alcohol, and then pour this into a vial and let it sit out for a day or two to allow the alcohol to evaporate. Trying to transfer the oil into a small container while it is still solvated by the butane is too risky. I learned the hard way about this, thanks to the volatile temperament of butane. I had filled a vial almost all the way to the top and was preparing to drop those last couple drops in, so that cleverly, I could let the last of the butane evaporate from the vial and the oil would all be neatly contained. But when the last drop hit the mother lode in the vial, it changed the temperature of the solution in the vial upward by a hair and it all "superboiled" out of the vial and onto my fingers, which of course startled me and caused me to drop the vial. I suggest dissolving it in alcohol as I mentioned above. If you can get pure or 99% isopropanol (isopropyl), use it, because THC's photosensitivity reportedly does not occur in isopropanol.

The final product is a deep yellow-amber oil of the highest quality, incredibly pure and potent. I remember well some of the prime "honey oil" hash oils that hit the market in the late 1970s, and this stuff stands up to (if not exceeds) any of them. It's amazing how this method extracts only the good fraction and leaves the junk in the weed. But that's exactly what it does. Note also that this oil has a somewhat higher melt/vaporization point than traditional hash oils; the traditional dispensing method (dipping a needle or paper clip in, getting some goop on the end, and warming it with a flame to get it to drip off into your bowl) still works with this stuff, but it seems you have to be more careful with it because it doesn't heat to liquid state as quickly or in the same manner, and it can more easily be allowed to burn up on your needle. So be careful.

There should be no remaining solvent smells when the oil is finished. If there are, the oil needs more time to evaporate off the butane.

Those who prefer a tincture-like preparation can of course thin the product a little with a bit of warm high-percentage alcohol like Everclear or 90-whatever-% isopropyl, then drop it onto buds or let a joint absorb some, then let the alcohol evaporate. I also observed that unlike hash oil derived from traditional methods, this product is not immediately soluble in room-temp alcohol; it needed to be warmed before it dissolved fully.

So there it is. Spread the word far and wide: honey oil is BACK!

[Erowid Note: Some concern has been expressed about the possibility of a PVC residue in the final product. This has not been verified, but a possible solution would be to use steel instead. Some reliable chemists have stated that PVC should be resistant to butane, but a preliminary flush of the PVC to remove any residue left from production might be warranted.

Opinions differ about how much PVC interacts with or is dissolved by butane, but a number of PVC chemical resistance tables used in the plastics industry indicate that PVC and butane do not interact much. According to the "PVC Chemical Reistance Guide: First Edition", 2009, by IPEX, butane is marked as "R : Generally Resistant". According to Spilltech's "PVC CHEMICAL RESISTANCE CHART", Butane is "Good / No data available". It should be noted that there are many different forms of PVC, from clear, flexible tubing to the more rigid opaque white "schedule 40" pipe used for drinking water lines. The flexible, clear PVC is likely NOT suitable to use with butane.

Many people report using stainless steel turkey basters as small, home alternatives to PVC. Some turkey basters have tips that can fit into or around a butane can nozzle.]

• Comments on the Honey Hash Oil Technique - by Anonymous
• Honey Oil Butane Extraction Tips - by Phife