Purifying through cold (winterizing) Non Polar extracted cannabis concentrate with ETHANOL (AVOID methanol and isopropanol, don’t risk dying, trying to save a couple bucks, to stay healthy!)
This process takes BHO, HHO (Hexane Hash Oil,) shatter, wax, dry ice hash, and bubble hash, and purifies them, from 30%-60% pure to +90% pure. The resulting OIL is a volatile (flammable) oil that will wick and vaporize, is per-decarboxilated, so it can be dissolved in oils or alcohols for consumption, without heating, and can be “dabbed” or vaporized with a nectar collector. It is roughly 2-4 times more concentrated than regular oils, because impurities, including those brought in by solvents, are removed.
As with any process that uses a flammable solvent, be sure to have a proper recapture system and hood in place, as vaporizing outdoors may violate environmental laws or regulations in your region. Have a properly rated fire extinguisher handy, and realize that it will explode in the 1920c/3,488f flame front - the exploding flame front, that also consumes your flesh as you scream, if you don’t heed this warning and ignite alcohol vapors in an enclosed area.
What you will need:
Ethanol 45ml (roughly 1.5 oz) per gram to be cleaned – 195 proof Everclear, anything less will have too much water and will require a freeze and roll step, to expel the water.
Scientific* Glass or stainless stir straw/stick
Scientific* Glass measure (500ml,) ml measures are more precise, and allow conversions between weight and volume more easily.
vacuum chamber that fits in double boiler, realize that alcohol will condense in the line, and a bleeder is recommended.
Vacuum pump – again, alcohol condenses at a higher temperature than Butane or Hexane, Keep an eye on your vacuum pump vapor and pressure as early indicators that alcohol is condensing in the line!
IR hotplate, digital hotplate, or hotplate and candy thermometer to dial in temperature.
3 jars (quart, large mouth mason jars.)
freezer – deep freezer is best (-18 to -30)
Filters – fine screen (such as with a “blast tube,”) and cone coffee filters. (Natural filters are more fine. I generally use 10-15 filters per 900ml of slurry that I filter.)
Patience and ability to follow directions (see horrible flaming death warning, above.)
*Scientific glass is a reference to heat tempered/high heat resistant borosilicate glass. Glass heated and cooled rapidly can shatter, unless tempering and materials are appropriate for the heat/cool process.
Step 1: In a clean jar, dissolve your unfiltered concentrate at a ratio of 1 gram of concentrate to 45 ml ethanol, stirring until fully dissolved.
A. I find it a waste to do less than 20 grams of concentrate at a time - 900ml of ethanol.
Step 2: Place slurry in freezer for 24 hours, undisturbed.
A. The waxes in the oil will begin to coagulate and gather other impurities that are not polar. (impurities such as micro plant matter, waxes and lipids extracted with the butane will not dissolve in alcohol, they are non-polar.)
B. If properly left undisturbed, a whitish slurry will form on the bottom of the jar, and the liquid will become clarified, while the color will be honey to amber, the liquid will become very transparent.
Step 3: Remove liquid from freezer and CAREFULLY pour 450ml into measuring cup, place cone filter over mouth of jar, using screw-top to secure in place.
A. Make sure the jar is new and CLEAN (no dust, no resin, nothing. Pure, clean.)
B. Place jar with remaining slurry back in freezer.
C. If you have a glass siphon, that’s the optimal method for removing the top liquids, without disturbing the contaminated bottom slurry.
Step 4. Place measured slurry in freezer for 30 minutes, to ensure separation and cold temperature
A. To help keep contaminants coagulated, place filter jars and screen filter in freezer, when not actively working with them.
Step 5. Form screen into concave filter, pour alcohol through screen and into filter, being sure to go slow, and clear screen while waiting on filter to drain into jar.
A. If filter begins to plug (as evidence by a stop in draining,) carefully remove and pour back into measuring cup, replace filter, and continue. Do NOT attempt to stir or force through, or you’ll break the wax up and it will pass into your purified alcohol wash.
B. When all alcohol is filtered into wash, place a clean filter over the face out (allowing for evaporation of alcohol,) and place aside (OUTSIDE!)
Step 6. Repeat steps 3 through 5. with remainder of slurry. This will take longer, and will use more filters, as the whitish slurry will be filtered at this step. COLD IS KEY!
Step 7. Combine liquid in filtered jars to make the next steps easier, a round glass
A. A Pyrex pan that fits inside your vacuum chamber makes the remaining steps much easier! Just be sure that it will hold at least 3x the volume. (For example: 4 quart round for a 1 quart jar full is what I use.) I do not use silicone, If you don't have a Pyrex option, and use silicone, than line your vacuum chamber to hold 3x the volume.
Step 8. Using extraction chamber bass and double boiler, bring water to a boil to heat alcohol. DO NOT DO THIS UNDER VACUUM UNLESS USING A RACAP SYSTEM!
Step 9. Monitor progress of distillation, when reduced by ¾ (900ml will reduce to approximately 225ml,) reduce heat to 100f/38c, remove chamber from boiler, cool, and fit vacuum lid.
Step 10: Replace in warm double boiler and vacuum purge, at -25 bar, and 100f/38c for 24 hours. Again MONITOR YOUR VACUUM, ESPECIALLY AT FIRST! YOU WILL GET ALCOHOL CONDENSATE IN THE LINE!
The low temperature will help to preserve the integrity of your terpenes and cannabinoids, higher temperatures will distill light terps, and destroy some cannabinoids, it will also change the chemical make up of your concentrate.
Remember, I am at 6,000 feet above sea level. While the vacuum temperatures are static (the pressure of -25 bars is the same at 6000 and 200 feet. The boiling points, UNDER VACUUM, will be sea level independent, anything done outside the vacuum is directly affected by your altitude. For instance, water boils at 201 degrees here, and alcohol boils at just under 162.)