Here’s my first cold extraction! Did a small scale 1 ounce extraction to start to get a feel for it. Here’s how it went:
Part A, Extraction:
1 Cooler full of dry ice
1 oz chilled cannabis
2 insulated to-go mugs
1 mortar and pestle
1 coffee filter
1 thermal probe+multimeter
- Pour ethanol into to-go mug
- Add dry ice and wait until temperature reaches approximately -67°C
- Crush chilled cannabis coarsely while ethanol cools
- Add crushed cannabis to empty to-go mug
- Pour chilled volume of ethanol into cannabis
- Wait 10 minutes
- Pour loose ethanol into coffee filter and wait to filter out
- Put mass of cannabis into cheesecloth and wring out into coffee filter
Problems with my extraction:
A. Poured the dry ice in with the ethanol into the cannabis to keep temperature. Made it a bit difficult to get soaked cannabis for wringing. How do people keep ethanol cold during the soak? Does it warm up substantially?
B. Forgot to keep cannabis chilled after crushing, so probably picked up extra water-solubles on initial ethanol pour
C. Coffee filters aren’t fine enough, and with precipitated waxes, takes a long time to filter through.
D. Cheesecloth wringing is a bad way to recover ethanol so my ethanol recovery is going to be rather lacking (I know, I should get a panda!)
E. Not cold enough imo. We were barely hitting the -67 threshold, and I’d love to hear how you guys are maintaining colder than that.
Part B, winterization 1:
1 Results from part A
1 Cooler of dry ice
1 Vacuum pump + tubing
1 Vacuum funnel
1 Receiving flask
- Keep results from extraction in mason jar overnight in dry ice to precipitate waxes
- Put coffee filter inside vacuum funnel
- Run vacuum and pour ethanol through coffee filter
Problems with winterization 1:
A. No regulator on vacuum pump means the vac draws a bit too hard for my flask
B. No micron filter means some number of waxes got through, coffee filters are too coarse.
Notes for the future:
A. No regulator on my vacuum pump means no control over my rotavap; all I can draw is max vacuum.
B. Micron filter paper is coming Monday, so I can do my second winterization and get rid of some more of that cloudiness in the extract.
Rotavap step comes next, it’ll be my first time using the roto as well. I’m excited!