Cannabis Alchemy

by D.Gold

Purification

Oil produced using this method is quite potent, but still contains substances which give the oil its taste, smell, and color. These are sometimes very pleasant to smoke, and they are sometimes left in the oil. Removing them, however, greatly increases the potency, but decreases the yield proportionally.

The oil from the extraction is dissolved in five times its weight of alcohol and poured into an equal volume of water in a large glass jug with a screw-on cap. All solvents used are cold or cool. A volume of petroleum ether equal to half the volume of the water used is added. The screw top is tightened and the jug is inverted. The jug is turned upright immediately, and a few seconds later, when the mixture has run down the sides of the jug, the screw cap is opened slowly to relieve the pressure. The inversion of the jug is repeated about twenty-five times, which releases the pressure each time, and then the jug is allowed to sit for about half an hour. The mixture of liquids will separate into three distinct layers. The bottom layer will contain water, alcohol, and the substances in the oil (tars and resins) that are not soluble in petroleum ether. The thin middle layer is an emulsion of waxes, ether, and air bubbles. The top layer is the purified oil dissolved in petroleum ether.

The jug is fitted with a two-holed rubber stopper, glass tubing, and rubber hose. Two pieces of glass tubing are fitted into the two-holed rubber stopper. (Injuries when cutting and fitting glass tubing are frequent—cut ends are always fire-polished and hands must be protected when any force is used in fitting the tubing.) One piece of tubing need only protrude from the stopper an inch on each side. The other tube is positioned so that when the stopper is tightly fitted to the jug, the tube extends into the mixture to a half-inch from the bottom of the ether/oil layer. The other end of the tube is attached to a length of rubber tubing to transfer the ether/oil solution to a collection jug. The end of the tubing must be lower than the end of the tube in the ether/oil solution in order to obtain a siphon action. A short piece of rubber tubing is fitted to the short glass tube, and air pressure is applied to start the siphon. The glass tube is spaced a bit above the emulsion layer; any ether/oil solution not removed will be recovered later. The ether/oil solution in the collection jug is saved. Another volume of fresh petroleum ether is added to the extraction by inverting, separating, and collecting the ether solution, which is added to the first ether/oil solution. This process is repeated until the ether layer remains clear after inverting. This indicates that the ether-soluble oil is totally extracted from the alcohol-and-water layer. No more than several ounces of the combined ether/oil solution is put in the stainless-steel pot, and the collection pan is placed in the colander. The apparatus is reassembled, as was done for the removal of the solvent from the oil after soxhleting. The rig is placed in the water bath and slowly heated to 140°F. After evaporating and collecting the ether (saved for future use), the stainless-steel pot with the oil is put into a boiling water bath for several minutes and stirred occasionally to remove any residual traces of solvent. The refined oil thus obtained is much superior to the oil obtained from the original alcohol extraction.