Hello, I am looking for some particular information to solve issues on the distillation system I work with. So I’m getting from low 80’s to mid 90’s percent on THC. I need 90 and above. I also get darker distillate in the beginning of the run and it clears up about half way through. Sometimes I also get what looks like a thin brown/black streak coming through with the distillate. Making it darker. Seems like residue passing through somehow. Some runs seems to have pretty low results and some pretty high. Could be based on material going through maybe? Material can range from pretty fresh or years old. But the biggest issues are potency. I recently had a batch of high quality bud going through but the distillate came out really dark. But prior to that batch I ran a really old batch and it came out lighter. But it seems like anytime I have older product come through I need to bump up my condenser to 90C. Higher quality stuff does fine on 70C condenser. I am very willing to give any more details. I have a lot of questions and I’ve done a lot of research and reading but it seems like everyones systems are slightly different. So I figured I’d reach out to get some clarification on things. Sorry that this post is such a mess.
Welcome to the forum @Azurath
Any additional info you can share will be helpful to try and figure out whats going on with your run.
From what im reading it would seem its heads in the beginning of the run and tails (streaks) coming after youve collected mains. Throw your parameters and what gear you are using.
So my parameters are
First pass
Feed - 70c
Evaporator - 150c
Condenser - 25c
Residue - 120c
Vacuum - .025 - .001 torr
Feed speed - 20 on the device. Not too sure on the actual input speed
Wipers - 350 on the device
Second pass
Feed - 70c
Evaporator - ranges from 165c-170c I adjust depending on batches
Condenser - ranges from 65c-70c or 90c
Residue - 130c
Vacuum - .025-.001 torr
Feed - from 8-10
Wipers - 350
I really appreciate the advice. It’s been frustrating but I understand that all these parameters make it feel like there is near limitless variations. Especially if accounting for prior procedures.
Try cranking your condenser up to 100-110c on your second pass to help reject more tails that may be coming off, and of course shoot for as deep of a vac as possible during your second pass. Keep your vac up around 1.0torr for the first pass (assuming it’s a terp strip). A deeper vac during terp strip just encourages THC loss (ends up in your terp cut), bumping your wiper and feed speed up (the feed speed more than the wiper really) during your terp cut helps to A - push more material through faster, and B - reduce residence time during a terp cut. If you find that you are losing efficacy during your terp cut, ramp your evaporator temp up 5c at a time till you’re where you want to be, as the faster you push stuff through during a terp cut, the less time it has to actually warm up to the temp the evaporator is at.
If you know what hot-condensing short path distillation is, then you know how a wiper works, and you know that your condenser is likely not quite as hot as you’d like it to be during your 2nd pass.
Again, this is all assuming that your first pass is a terp cut, which it appears to be, excluding the stated vac depth.
My experience tells me that variations in distillation performance have more to do with extraction performance than distillation parameters. How reliable is your extractor?
And as always, clean your rig between runs.
Failure to decarb completely can cause splashing from evaporator to condenser…
How are you ensuring decarb?
Have you read through Condenser is truth. Wfe settings
This could be from splashing or a dirty condenser
If you didnt clean the machine before hand just push a few liters through till its the color you want then rerun the darker stuff from the beginning
Is this a glass or steel unit?
Id up the temp on your feed too 70 is low and will cause your oil to have to be heated up in the wiper body thus effecting efficiency first and second pass
I like my feed at 110-120 personally
I keep mine at 100c, and was thinking about lowering it, thank you for reminding me why I shouldnt!
It’s important to remember that the distillation thats occuring at the top of the wiper is different from that which is occuring by the time the crude is near the bottom of the wiper. Feed temp is a powerful way to manage that.
(and now I want a top pullin’ external condenser to handle the “heads” fraction)
Residence time is important too. I feed my wipers faster then most but I also run hot which you can do if you feed it fast. First pass is fast and hot to get a clean cut of disty away from the crude and get as much out as possible (i terp strip in a reactor and since im running hot condenser tech i can blow the heavy heads to the cold trap)
Second pass is a little lower and slower but not by much. Its easier to cut out the tails on second pass once the heavy heads are out since your vacuum is better.
To each either own though
I wish I had a reactor 
Our lab was equipped with a 100L ecodyst “because it can decarb as well!” …
I’m chained to the worlds least reliable and most expensive rotovap in 2025
So you don’t like the Ecodyst and would prefer a rotovap instead? My lab has one with their Ecochyll x7. Someone in the before me time broke the glass lid. I have replaced the broken parts with a new metal lid setup that they offer now. We were wanting to hook it back up because I hate having to deal with a heavy 50L globe rotovap. I was thinking that being able to reclaim etoh and then decarb in the vessel and transfer to a pot via the exit port would be amazing.
I had one of the original eco dyst in a lab i was working for, originally they had PE tubing connecting the vessel to the cooling coils
Needless to say i collapsed that tubing decarbing under vacuum
They started using that steel braided hose on their units after that
No I want a falling film, but i’ll take a rotovap over an ecodyst hell yeah brother!
The primary issue with ecodysts is the direct-heat mantle (and of course the slow recovery speeds relative to modern solutions) and their controllers, at least for the larger volume set-ups. Company I work for have had an implosion, and an explosion with them, and we for some reason keep spending money on new glass to keep them operational, even though a silver serpent is like, $30,000 these days.
Plus, you can decarb on a hotplate, for what reason would one want to spend six figures to decarb in their rotovap? Like, just get a rotovap siphon tube, and send me the money you save, yeah? No need to pour out from the bulb directly, it’s 2025.
Like the glass globe had an implosion or an explosion? If that’s the case then I would never even consider running in my lab.
Both! It’s one of the reasons why they offer steel lids now. Different facility than the one I’m at, but they sent it to us when they got a falling film as a replacement… . . .
It’s a company that’s literally R&Ding their product live in other companies lab room floors. Completely unacceptable, especially at six fuckin’ figures.
Only neat thing about ecodysts is their condenser design. Would recommend purchasing just a standalone condenser from them, totally.
Dang. Well f that then. I was wondering how the glass top got cracked. Probably what you mentioned. Scary. And, for my lab location we can’t use the metal keg for collection. Has to be glass. And of course changing anything from the original setup requires it be re-inspected/tested. Thanks for sharing your experience with ecodyst. It looks neat on youtube videos, but if it recovers slower than a 50L rotovap well that’s worthless.
If your lab is willing to spend the money, I’d recommend a falling film evaporator from Trusteel, or bizzybee, or possibly from USAlabs, but their price is questionably low, so I’d steer clear from USAlabs unless you’re willing to pick up a project essentially…
I def want falling film. There’s no money for new equipment. Boo. Whatever I’m getting buff using the 50L rotovap.
Talk to…I believe beaker & wrench…about a rotovap siphon tube.
You can make one yourself, or have a local glassblower make one, if those are options for you.
Its basically just a feedtube that dips all the way into the bulb itself to allow an operator to siphon their crude out of the bulb without having to remove it. Recommend something durable, and ideally heated, for reasons.
Interesting idea. I’ll call Ace on Monday. I run the B&W 6in wiped film. Freaking love that machine!
Hound bidspotter and eBay. There’s no reason to buy new in this market. If you’re already patient enough to run without the equipment, wait until one hits the usual gettin spots and pick one up on a steal. That’s how I built out my entire lab. The deals I got on different things is absolutely insane. I averaged less than 25% of retail on just about everything.