There’s no denying the facts anymore: dabbing has become the premiere method cannabis consumption among weed connoisseurs. The golden, terpene rich concentrates available on the market today are a vast improvement from the dark, harsh oils that were once mass produced only years ago thanks largely to improvements in commercially available extractions systems.
These “closed loop” systems have not only improved overall quality of products on the market but they also offer much greater safety profile in comparison to the old popular “open blasting” techniques responsible for creating lower quality concentrate (not to mention ‘explosive’ headlines for the newspapers). A simple google search will show that these “closed loop” systems cost thousands of dollars and require special tanks and vacuum pumps but in fact, one can use the same principles to produce very high quality shatter / live resin for a fraction of the price. In this article, we will outline a simple, closed-system method of extracting cannabis to produce the highest quality extracts for under $400.
Disclaimer: The following information is for educational purposes only! Solvent-based cannabis extractions are illegal under federal and local drug lab laws and can be extremely dangerous. Such extractions should only be performed by trained professionals in licensed facilities in compliance with local laws and regulations.
A “closed loop” extraction system is one in which butane is constantly run over resin-rich plant material where it solvates THC, enters a collection chamber, evaporates, and then is re-condensed to be re-run over cannabis again (thus reducing the amount of solvent needed). As a cheaper alternative, we will be electing to use a “pressurized closed soak” method where butane and cannabis will be combined in a closed, pressurized column and allowed to soak for 45 minutes to ensure extraction efficiency. With this method, butane cannot be recycled (it must be evaporated off into the atmosphere, a costly prospect for mass production) but the quality of product is top tier and one can produce some incredible live resins when the extraction is done correctly and with care. It is an excellent alternative for people who wish to make smaller, less frequent batches of concentrates. For this method, you will need the following:
- 1x Triclamp sanitary stainless steel spool (1.5” diameter, length depending on how much material you wish to run, we suggest anywhere from 6”-36”)
- 1x Triclamp VITON screen gasket 20 mesh (1.5” diameter)
- 1x Triclamp VITON gasket (1.5” diameter)
- 2x Triclamp top cap w/ lance valve (matching diameter)
- 2x Single pin triclamp (bestvacs includes one with legs welded on)
(bestvaluevacs.com sells all of the above as a kit starting at $170)
- 1x FJC vacuum pump, 1.5cfm and ($80 at Harbor Freight)
- 1x vacuum chamber and appropriate vacuum hosing (you can try to make your own but good ones can be purchased for $100 online)
- 1x case of butane (Whip-it! Sells the most pure canisters and they contain 400ml whereas most other brands come in 300ml canisters)
- 1x pyrex dish
- 1x Parchment paper
- 1x Dank marijuanas, preferably freshly cut and frozen buds for live resin.
- (optional) a pot of hot water a.k.a. a hot water bath.
- (optional) dry ice and a cooler / container that will fit your spool with the end caps on.
The dry ice is particularly important if you wish to make live resin. If using cured buds, the cooling process is less essential but will still help create a lighter, more desirable extract.
Step 1: Prepare Buds Collect your plant material use your hands to break down larger nugs into a more manageable size as we will be packing the plant material into the stainless steel spool / column. You want to avoid grinding the buds because cutting the plant cell wall will allow chlorophyll to be more readily extracted by our butane resulting in a darker color and harsher taste (remember, all THC is on the OUTSIDE of the plant leaf in the trichomes!). Frozen buds are particularly brittle and easy to “nug bust” by hand in a plastic bag so even if you aren’t making live resin with fresh frozen buds, we recommend you freeze your plant material anyway (remember to remove as much air as possible from the bag to reduce the formation of ice crystals)
Step 2: Pack the Column Now that your buds are broken down into ~5mm particles, you’ll want to gently pack your stainless steel column with the mesh screen clamped to the bottom to prevent buds from falling all the way through. The key is to not pack the tube too tightly or else butane will form channels in the column and some buds won’t come in contact with the solvent. Use a rod of some kind to tamp down the plant material in the tube every few grams or so to ensure even packing. Once the column is packed completely, secure the final gasket and top cap with your second clamp and close both valves on either end of your extractor. If you are making live resin or have dry ice and a cooler available, you should allow your tube to cool under the dry ice for at least 20 minutes to ensure buds (and residual water) inside are completely frozen. WARNING: the metal will be cold enough to burn your skin, use insulated gloves (or oven mits) to protect your hands!
Step 3: Vacuum and Extraction Time to use that vacuum pump! Attach the vacuum to the bottom of the extractor (the side with the mesh screen) using your vacuum hose, open the bottom valve and pull vacuum on your extractor column. It shouldn’t take more than a second and you will be able to hear the vacuum make a softer gurgle once its reached maximum vacuum. Cycle the valve (open and close it) twice to make sure you’ve pulled as much vacuum as you can, then close the valve and turn off the vacuum pump (the FJC model allows you to release pressure via a screwable cap where the hose attaches, this will make it easier to remove the hose from your extractor once its under vac). Now it’s time to make the magic happen! Selecting the appropriate adapter from the butane canister cap you can directly inject butane into the top of the extractor by opening the valve. The negative pressure will suck butane into the column so be sure your canister is releasing butane just before you open the top valve on your extractor (or else you’ll suck in air which takes up butane space!). Listen closely to the butane canister— once the column is fully pressurized with butane you will hear the butane stop flowing from the canister. You may need to use more than one canister depending on how big your column is. After the column has been fully pressurized with butane, we suggest you place the entire primed extractor back into your dry ice cooler (if you have one/ are making live resin). The cold temperature reduces the solubility of water and other undesirables in butane which always leads to lighter colored, more desirable extracts.
Step 4: Separate Mother Liquor After about 45 minutes, your extraction will have reached optimal completeness. Remove your extractor from the cold and with your pyrex dish placed carefully underneath your bottom valve, slowly and gently turn the valve so butane begins to drip into the dish. If you release the valve too quickly, butane will spew out and create a giant, flammable, sticky mess. Controlled flow is key! Cycle the valve (open and close it) when the butane stream starts to sputter to allow gasses from the top of the column to push liquid down through the bottom. When there’s little butane left, place the column outside and release both valves to allow residual butane gas to escape. You now have a pyrex dish filled with our butane mother liquor and it should have a vibrant yellow color to it. You can attempt to try another run with the spent material but its rarely worth the solvent required as the first extraction tends to capture 80-90% of the desired cannabinoids.
Step 5: Purge the Solvent The final step is the removal of excess butane which can be detected by taste at even a few hundred ppm. Leaving your pyrex dish of mother liquor in a well ventilated area will allow much of the butane to evaporate off but to speed things up we recommend placing your pyrex dish in a another bowl of shallow warm water (remember, butane is highly flammable so be sure the dish is nowhere near any open flames— warm the water up elsewhere!) Once the liquid has reduced substantially (but not completely), its recommended to pour off the thickening resin into a dish lined with parchment paper so your final product is easier to remove. All that’s left is to throw this dish into your vacuum chamber and pull the chamber down to about -28 mmHG (or as far as you can take it). Most people like to leave it under vacuum for as long as 24 hours but you can achieve a faster purge by cycling the pressure of the chamber every hour or so (placing your chamber in a warm water bath will also speed things up). You should be left with a beautiful, golden terpy sap! The final test is the taste test (don’t worry, butane is essentially non-toxic) and you will be able to tell if your extraction needs some extra purging or if you did things just right!
It can seem a bit overwhelming at first but the process is rather straightforward. In short, the best extractions are done as cold as possible with the strongest, freshest material one can find. Cured buds will produce less tasty, colorful extracts but this “closed column” method both reduces the amount of butane necessary and provides an significantly safer method to open blasting (albeit slightly more complicated and expensive). Of course unless you have access to cheap, high quality bud… it’s almost always more economical (and safer) to purchase from the experts! Remember, you can go to jail for making this stuff (but not necessarily possessing it). Consider your risks carefully and stay lifted!