Hi folks. Created an account here just to share this. I've spent the last year and a halfish tinkering and experimenting and I finally feel ready to bring to the world a culmination of my efforts thus far. For my own security I'm not enthusiastic about sharing pictures of any of my setup or this method; you'll have to take my word for it I've done this and gotten these yields, and run the extraction yourself (if you have the equipment) to corroborate my results.
Miscellaneous jars are beneath this community. We can do better. I've gone out into the world in search of methodology and equipment which can be more rigorous, reproducible, and easily operated. I read most every extraction tek listed on this site when I began to inform the development of my own tek, as well as miscellaneous trawling, hemming and hawing through reddit, and identified that the key bottleneck common across extraction teks is the difficulty of handling the biphasic liquid system and finding ways to minimize contact between bark/solvent and anything that's not glass or stainless steel. A somehow completely separate and unrelated foray in my life introduced me to the system of ground glass joint glassware, which eliminates these problems. I'm not going to pause to explain much of that terminology, if I lose you watch some Nilered and come back.
Like most people, I eagerly tried out doing pulls using a sep funnel, only to have the stopcock clog on my first pull. I feel like many people see a sunk cost and avoid potential fallacy at this stage, falling back to their previous pulling system. Already having way more glassware than a sep funnel laying around, I kept tinkering. Vacuum filtration doesn't seem to behave too well and I find the idea of adding a pH swap into the tek just to filter iffy; this is a planned future area of research for me.
Enough waffling. All temperatures are Celsius. I call it "Glasstek":
Necessary equipment:
2x 1L 24/40 Round Bottom single-neck boiling flask (optional: one one neck, flask, one two-neck flask with a thermometer adapter)
2x 1L Beaker (will be called "large beakers"
2x ≤500ml Beaker (one will do)
1x 50m ground glass syringe (preferably also with a set of all-steel luer lock needles, as opposed to luer lock needles with any plastic components) (if you don't wanna clean mid-process just get five)
1x 1L heating mantle with magnetic stirring
1x Hot plate with magnetic stirring
1x big boi PTFE magnetic stir bar (the biggest) (mine is 50mm)
1x 24/40 300mm Liebig condenser
1x 24/40 300mm Allihn condenser (optional)
1x glass dish for freeze precipiation
A 24/40 75 degree still head, and a 105 degree 24/40 vacuum takeoff adapter (or your preferred trimmings for simple distillation)
A small immersion water pump, a bucket, and appropriate tubing to adapt the pump to the water inlets/outlets of the condensers
A lab stand and one clamp
A funnel resistant to nonpolar solvent and high/low pH (recommended: a glass funnel with a 24/40 joint)
A glass stir rod
A glass eyedropped graduated in single milliliters
A lid the RBFs will sit on in a well-behaved manner (I've found purpose-made cork rings tend to be too tall for the stirring to work effectively)
Optional: IR thermometer
Necessary chemicals:
- Approx 1l of heptanes (hexanes or pentanes will be too volatile for the pulling process here, best to stick with the higher boiling saturated hydrocarbons.) Naphtha is NOT an acceptable substitute, you need a solvent that won't fractionate when it boils
- Sodium hydroxide
- Concentrated HCl (mine claims to be 32% and certainly fumes enough to be)
- Distilled water (tap water is *fine*...)
- Pure NaCl (often sold as a canning or pickling salt, I hear ice cream salt also lacks anticaking agents and iodide)
- Powdered plant material (I use MHRB)
Method:
Step 1: Acid cook setup
Preheat your heating mantle and use the lab stand to loosely clamp the condenser in a vertical position (use the Ahlin if you have it). Bring 500ml of water to a boil in the microwave while measuring out 50g of plant material. Gently add the stir bar to one of the round bottom flasks (if you have a two-neck, the two-neck, with a thermometer inlet adapter and thermometer in the second neck), then pour in the water. Place the flask on the hot plate with stirring, resting on the lid, such that you can trust the flask not to fall over if you don't hold it for a few seconds. Turn on the stirring, and adjust it to the highest level it will stay stable at, this should be a vigorous vortex. Using your funnel, slowly add the plant material, pausing additions to allow clumps to be broken up. Turn on the stirring on the heating mantle, and adjust to a setting above the minimum but still low.
This bit is tricky- the bark has to stay moving in solution or it'll weigh down the stir bar and clog your stirring in a heartbeat. While the flask is still stirring well on the plate, quickly transfer it to the mantle. Experience is an irreplaceable teacher, at this step, for being able to hear whether or not the heating mantle has properly engaged the stirring. Ensure the mantle is properly stirring before proceeding to (very carefully, duh) add exactly one milliliter of the concentrated HCl. Once this is added, put the condenser in the neck of the flask.
Step 2: Acid cook
Experience is once again irreplaceable for knowing what heat setting on your heating mantle will produce a stable boil. Adjust the heat to this level, and when the solution begins to boil, start a timer for three hours. You won't need any ice in the condenser water, it will stay room temp, and unless you're overheating the solution it will boil in a stable and well-behaved manner. If there's more than an inch of foam, you are applying too much heat. If the foam goes over three inches, you are applying WAY too much heat, it's gonna keep going all the way up your condenser and out of the setup (the heating mantle will catch most of it). Pour 50ml or so of water down the condenser to momentarily quench the boil while the excess heat in the mantle dissipates. This is where having a two-neck flask and a way to put a thermometer in the second neck comes in handy for temperature control. If you did steps 1 and 2 in a timely manner your solution should be no less than 70 degrees when you're turning the heat on.
Step 3: Basification:
Y'all are gonna give me so much shit for how I do this step but this is my method and it's my method. If you don't like this step you can do it differently but if you get lower yields I reserve I-told-you-so-rights.
When the three hour timer is up, turn off the heat. Wait for the boil to subside, then loosen the clamp holding the condenser where it attaches to the stand, such that you can pull the condenser up and out of the flask neck before retightening slightly and rotating the clamp so the condenser is out of the way of the space above the flask. Insert your funnel. Weight out 11.5 grams of lye, set aside, and then VERY carefully and SLOWLY, sprinkle in small amounts of lye (not from the measured amount). It should turn the solution grey wherever it touches it; keep adding very small amounts until the grey color persists across more than half the surface of the solution. You're aiming very crudely for a neutral pH; I've found this is the best visual indicator. After that, start very slowly adding the measured amount of lye. The hygroscopic nature of lye and the excess water vapor in the flask will be a recipe for the lye sticking to the inside of the funnel; this is okay. Just go very slowly, waiting for all the boiling to subside before adding the next smidge, regularly pushing what gets stuck in the funnel down into the flask. Once it's all in solution or stuck in the funnel, rinse with 20-50ml of water to get all the lye into the solution. It is more than possible to do this without the heat of the lye dissolving to cause the solution to boil out of control; much the same as you won't get hyperslapped unless you're acting a fool you won't have the solution lash out in anger unless your hubris is pissing it off.
Step 4: Base cook
Once the lye is rinsed into the flask, replace the condenser in the neck and set the heat back to a level for reflux. The solution should very quickly get back to stable boil/reflux, when this visually occurs, start a 90 minute timer.
Step 5: Setup for pulls
When the 90 minute timer goes off, turn off the heat on the mantle, and preheat the hot plate to 90-100 degrees. Place one of the 1L beakers on the plate, and all three other beakers nearby. Wait for the boil to dissipate, then break down the reflux setup and put away the condenser (if it's the Ahlin, if you only have a Liebig, you now need to clean and dry the inside of the condenser). Pour the contents of the RBF into the beaker on the hot plate, and engage stirring. Quickly rinse the RBF with hot water and then ensure the inside will dry within an hour (I like to rinse with 99% iso for a faster dry). You are aiming to hold the solution on the plate between 65 and 75 degrees, preferably 71-73 or so. Weigh out 150g of NaCl, add it to the solution, and wait for it to dissolve.
Step 6: Pulls
This is the one that needs a very well-ventilated area.
Step 6a: Use one of the small, clean beakers to measure out 200ml of heptane. Add it to the solution on the hot plate.
Step 6b: The biphasic system should exhibit a robust resistance to emulsion provided it got enough heat during the base cook. For 15-90 seconds, use the strongest stirring setting to emulsify the mixture, then adjust to a relatively low stirring speed and leave for 10-15 minutes. The emulsion should be completely gone by the time you return. If this upsets you you can also stir it at moderate speed for 10-15 minutes, this is just how I prefer to do things to maximize yield.
Step 6c: Use the ground glass syringe to suck up the heptane layer. Do not be alarmed if the heptane is still clear; there is spice in there, it's just not yellow. Dump these syringefulls into the small beaker not used for measuring heptane. It's just fine if some of the aqueous solution ends up in this beaker, it's there to catch that excess water so you can remove as much heptane as possible.
Try to avoid sticking your face right up by the beaker, you'll be watching each syringe pull very closely and it's easy to inadvertently get so close you're huffing heptane fumes. Don't do that.
Step 6d: When the whole pull is in the small beaker, carefully pour it into the other 1L beaker, being very careful to leave the droplets of bark solution behind. Recommended you cover this beaker between pulls to limit evaporation of the hot solvent.
Repeat steps 6a-6d five times. If you are doing good at getting all of each pull, and limiting evaporation well, you should have at least 900-925ml of pulls. If the fifth pull is yellow, that indicates you'll gain about 100mg of yield by doing a sixth pull. If you really want to be a madman, in theory ten 100ml pulls would be even more ideal than 5x 200ml.
Step 7: Heptane distillation
Now that the flask is clean and dry again, add your pulls to it. Set up for simple distillation using the two adapters. With only a 300mm liebig, the condenser water will have to be absolutely ice cold. The receiving flask should get a fog of condensation on it from the heptane coming over being not just condensed but also chilled. I typically reduce the volume to approximately 150ml by distillation; you can measure the amount of distillate with one of the beakers or just eyeball it how I do. The heptane that comes over will contain whatever water was in your pulls (it will be about as wet as heptane can be, really) but will be otherwise pure and ready to use again.
Sep 8: Freeze precipitation
Once the distillation setup is broken down and the final ~150ml of heptane has cooled from a boil, pour it from the flask to the glass dish, rinsing the flask with a little fresh heptane. Place this in a freezer set to less than -10 degrees, and wait 24-48 hours. You should yield at least 1.1-1.2 grams; I get 1.35 grams on the dot every time like clockwork.
I'm gonna add my notes on this process separately here instead of further annotating each step in the method above. Everything has thought and choice behind it.
Step 1: The numbers are definitely very round but they weren't chosen totally arbitrarily. The pH is the lowest I could reasonably assure wouldn't chemically harm the indole rings or do anything else weird. On paper it seems like a super strong pH (1.69ish) but then in practice watching the extraction go it almost seems like the acidity does nothing. Fickle thing. Homogenizing the bark and water for the first time was a real ordeal to figure out, which is totally not obvious from how simple I make it sound. I also scaled back a couple times, reducing the bark concentration to only 50g/500ml was the only way I was able to manage the foam, above 80g/500ml it is impossible to boil the solution without it foaming all the way up and out of the setup.
Step 2: This time interval was chosen after very uneventful trial and error. There's a certain well-behavedness to the foam that only appears after about two hours, and going for more than three hours has no observable effect on any part of the process. Also, I've been using a thermocouple stuck into my heating mantle for temperature control, and with a marker on the thermocouple wire so I insert it the same length into the mantle each time, it works great for monitoring how much heat the flask is actually getting. My thermocouple goes about 15mm deep between the flask and mantle and I get a lovely boil when it reads 170 degrees there.
Step 3: If you add the salt at this step, the flask will be stained with a bizarre, spikey, translucent insoluble residue centered around the stirring. Haven't figured out what's up with that, yet, but it only happens if you mix the lye and salt and add them together at this step. That was my solution for adding lye to hot solution being a dumb idea, cut it with the salt to absorb the excess heat, and while it made the addition totally manageable the stain on the flask is insoluble in everything in my wheelhouse and I'm baffled. Someone please explain this.
Also, the amount of lye was chosen based off a miracle I witnessed. In the course of my experimentation, I ran more or less this process, and somehow got GREEN product. I now religiously do this "neutralize by eye then 11.5g" process trying to repeat those results. No dice.
Step 4: The base cook is so well behaved. Every foaming issue I've ever had was in the acid cook. It's so good. I like to check on the acid cook at least once an hour but I'll forget about the base cook for its whole 90 minutes.
Step 5: The salt here is one of the only recognizable remnants of Cyb's AtB tek, which was a big inspiration for this one.
Step 6: The ground glass syringe is a godsend for making this whole extraction technique work. It's still... very tedious, though. Everything else is a cakewalk compared to the two hours you'll be bent over a beaker that reeks of gasoline, holding your hands as steady as you can as you slowly and surely suck up the pulls. I highly recommend making a playlist of your favorite focus music for this step.
Step 7: I hope I don't have to explain to anyone what "set up for simple distillation" means. I'll again point questioning readers towards Nilered on YouTube.
Step 8: Yeah, so, I get 1.35g from this method so very reliably. It's a little uncanny how reliable this is, I literally had two extractions both yield (by my measure) 1.349 grams. It's still a little spotty, adding the salt at the same time as the lye severely negatively impacts the yield for some reason, and last time I tried a sixth pull (the first three were clear and the next two were yellow????) I got 1.44g. So, like, that's a good yield, right? I've been thinking for a while this is sort of a "total extract' which gets both the spice and miscellaenous plant lipids, mostly because the freeze precipitation tends to yield both white fluffly crystals and an oily yellow substance, but I recently did a bioassay of the yellow oil and it was certainly very active, which leads me to believe the two substances are different expressions of the same blessed molecule, or at least the oil is only slightly impure. I imagine there's some way to convince all of the material to crystalize nicely and I seek it next, after I experiment with short path distillation.
Misc: The heptane distillation always takes longer than expected. You have to check it every 10 minutes or so or you WILL forget about it and let it go too far. I once evaporated off all the heptane and ended up with a beautiful (and annoying) frost of crystals all over the inside of the flask. There's probably also a good way to give the heptane a quick drying with some calcium chloride or mag sulfate or something, but I haven't been arsed yet. I am also, strangely, enough to note, frequently asked by the molecule to refrain from masturbation during this process. Rubbing a quick one out during the acid cook is okay cause that's the longest step, and idk why doing it during the base cook isn't kosher since it's another fairly unoccupied stretch of time, but I totally understand staying on task during the pulling process. Seems to be a respect thing, I've had a couple extractions go slightly pear-shaped because I disobeyed.
Whew, wall of text over. Thank you for reading. All input is appreciated; if anyone has the equipment to run this themselves and compare yields I'd be very curious to see if my 2+% yields are a result of the method or just a good single batch of bark.