greenfriend
ganja farmer
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- May 29, 2008
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I wanted to share some tips in live resin hydrocarbon extraction. This procedure is highly technical but will produce the highest quality live resin with just a small home lab setup. The other options are a $20-40k automated extraction system or paying $60/gram at the dispensary 
To make live resin you extract the plant material within hours of harvest. The result is a concentrate chock full of terpenes that tastes like nothing you've ever had!
The main obstacle in extracting fresh plant material is moisture that is undesirable in the end product. The sources of moisture are
1) The plant material
2) The ambient atmosphere
3) commercial butane
4) commercial CO2 (I'll explain why this is used)
Butane is the longest chain alkane that is still slightly water soluble at 0.0325 vol/vol (3.25%). That means that a liter of n-butane will actually hold as much as 32.5 ml or mgs of water.
Here is a good method to get dry HPLC grade n-butane. First, fractionally distill the butane, then pass it thru a column of activated alumina, then recondense to -20C and collect it in a evacuated Young's flask over a layer of Zeolite 3A.
To combat problem (1) the extraction is done at -20C to -70C. The moisture in the plant material will be solid ice.
This however introduces a new problem. When plant material is exposed to ambient air at -20C the water vapor from the air will condense and freeze on the plant material. This makes it hard for the butane to extract the cannabinoids. To solve problem (2), the extraction flask will be filled with an inert gas (CO2) to prevent ice condensation.
When you buy tanked CO2 it is likely to be contaminated with a little water. Dry it using a cold trap or U-tube packed with anhydrous calcium chloride before using it.
General Extraction Method:
1) Put freshly harvested buds in a Schlenk flask (sealed from ambient atmosphere)
2) Flush the flask with a stream of dry cold CO2 gas
3) Use Schlenk line to add dry butane (at -20C) from Young's flask
4) Soak the plant material
5) Evacuate vacuum purging chamber and use cannula transfer to move raw extract to vac chamber from Schlenk flask
6) Vac purge for along time at 5 deg C (NO HEAT)
Note: In step 2 you don't want to evacuate the flask with the buds in it. Since Co2 is heavier than air, heavy flushing will push the ambient air out the top of the flask. Colder CO2 is better (cold co2 sinks, warm air rises).
Alternative Solvent: Hexane, unlike butane, is not water soluble at all. Using hexane prevents any water from being extracted. However, hexane is hard to vac purge off, doing so would also remove the low weight volatile terpenes we are trying so hard to keep. Hexane is toxic to the CNS, to remove the hexane you MUST extracted the hexane oil with 100% ethanol, then purge the ethanol.
Last thing. Contrary to popular opinion, no one in the cannabis industry has discovered ANYTHING new about hydrocarbon cannabis extraction. All these extraction methods have been used on various flowers etc. for many decades by the perfume industry, among others.
Grow it. Extract it. Dab it.
To make live resin you extract the plant material within hours of harvest. The result is a concentrate chock full of terpenes that tastes like nothing you've ever had!
The main obstacle in extracting fresh plant material is moisture that is undesirable in the end product. The sources of moisture are
1) The plant material
2) The ambient atmosphere
3) commercial butane
4) commercial CO2 (I'll explain why this is used)
Butane is the longest chain alkane that is still slightly water soluble at 0.0325 vol/vol (3.25%). That means that a liter of n-butane will actually hold as much as 32.5 ml or mgs of water.
Here is a good method to get dry HPLC grade n-butane. First, fractionally distill the butane, then pass it thru a column of activated alumina, then recondense to -20C and collect it in a evacuated Young's flask over a layer of Zeolite 3A.
To combat problem (1) the extraction is done at -20C to -70C. The moisture in the plant material will be solid ice.
This however introduces a new problem. When plant material is exposed to ambient air at -20C the water vapor from the air will condense and freeze on the plant material. This makes it hard for the butane to extract the cannabinoids. To solve problem (2), the extraction flask will be filled with an inert gas (CO2) to prevent ice condensation.
When you buy tanked CO2 it is likely to be contaminated with a little water. Dry it using a cold trap or U-tube packed with anhydrous calcium chloride before using it.
General Extraction Method:
1) Put freshly harvested buds in a Schlenk flask (sealed from ambient atmosphere)
2) Flush the flask with a stream of dry cold CO2 gas
3) Use Schlenk line to add dry butane (at -20C) from Young's flask
4) Soak the plant material
5) Evacuate vacuum purging chamber and use cannula transfer to move raw extract to vac chamber from Schlenk flask
6) Vac purge for along time at 5 deg C (NO HEAT)
Note: In step 2 you don't want to evacuate the flask with the buds in it. Since Co2 is heavier than air, heavy flushing will push the ambient air out the top of the flask. Colder CO2 is better (cold co2 sinks, warm air rises).
Alternative Solvent: Hexane, unlike butane, is not water soluble at all. Using hexane prevents any water from being extracted. However, hexane is hard to vac purge off, doing so would also remove the low weight volatile terpenes we are trying so hard to keep. Hexane is toxic to the CNS, to remove the hexane you MUST extracted the hexane oil with 100% ethanol, then purge the ethanol.
Last thing. Contrary to popular opinion, no one in the cannabis industry has discovered ANYTHING new about hydrocarbon cannabis extraction. All these extraction methods have been used on various flowers etc. for many decades by the perfume industry, among others.
Grow it. Extract it. Dab it.
