Distillation run times

Hello everyone,

I’m currently running into some issues with how long my distillation run times are, and I’m wondering if anyone here can give me some tips. I’m currently running a 5L LS Executive G2 setup.

During first pass the lowest vacuum I can achieve is 40 microns, and the procedure I’m following is:

with fully decarbed oil, we heat up to 100C during startup, then to 150C, wait until vacuum comes down and vapor temp decrease before bumping it up 10C at a time until it gets to 170 mantle temp, then we increase mantle temp 5C at a time. We always wait until vapor temp and vacuum to come down before moving on to the next fraction.

Once we get to the mains and see distillate (Around 150C - 160C Vapor temp) , we bump up our mantle all the way to vapor temp 175C and hold it at that temperature and start collecting.

The issue here is that when we run a 5L with 2.5L crude, our runs can go from 14-16 hours. We’re wondering if there are any problems with our technique thats causing us to take so long.

Any help is appreciated. Thank you


What system are you running? I’d start with raising you BF temp until your vapor temp gets up around 180(even higher if running a hot first pass)


Sounds like you’re on the right path. You should be going at almost double that speed. How deep is your vacuum during the run?

push it hotter faster more aggressively. quickly get through your head fraction, and stay aggressively pushing the temperature up (without going too hot) the real key is to not let your vapor temp drop the whole time. you get nice separation by doing it the way you are, but thats not so much what we are after here. keep the vapor temp up, and push that shit out!


What kinda vacuum pump are you using?

What’s the flow rate in CFM? What’s the ultimate vacuum rating?


Controlling by mantle temp is tough because that is the temperature of the fiber glass of the heating mantle, not the temp of the liquid in your pot flask. There is always going to be some offset which you will get a feel for as you run it.

Like other people have said, go faster through the early parts where you are only trying to strip the junk out, not purify it. If you cared about the purity of terpene or other volatile, then you would want to go slow.

Take your time on getting a good heads cut. Most people get very greedy and I have seen people try to collect fractions over 100 C too low because they fall for the fools gold. If you are going through all the trouble of distilling this material a couple grams should not matter.


What are your boiling flask temperatures? Generally we’ll go straight to 175ish and let it drip out heads. With the kind of head you’re using on first pass for mains we usually go up to 193-195C boiling flask temperature. That should bring your run times down to about 8-10 hours with setup. Make sure you have an e30 or better pump and test for degradation afterwards, some heads will degrade oil at these temperatures


I’m running a Lab Society 5L Executive G2 short path system

My vacuum does not go any lower than 40 microns during the run

We’ve tried different experiments where we aggressively get through the head fraction and ramp up temperatures quicker, but after lab testing we see that the potency goes down if we don’t go through the heads fraction slower. When you say that I should keep the vapor temp up, do you mean just ramp up the temperature once I hit my mains fraction? so shoot it all the way to 220C right away and just let it distill?

I’m currently using the Welch CRV Pro 16 CFM Pump. Ultimate Vacuum rating is around 5 microns.

Do you have any specific vapor temp points to aim for when going through the distillation process? If I go from 0 all the way to 150C right away, wouldn’t I miss some fractions that I’m supposed to strip out, and end up with lower quality distillate?

From startup, I’d go straight to 193C? Wouldn’t I reach my mains fraction right away and would the heads fraction contaminate my distillate as well if I don’t take my time with my heads fraction?

dont do this. you dont want your vapor temp to be going up and down. once you begin your climb, dont let it dip. it can and should stop at specific temperatures, but dont let it drop.

you can try this, but you might have some degradation. but the idea is more or less correct. I would recommend experimenting with higher than 175 though if its too slow

It’s a little undersized but shouldn’t have problems holding vacuum unless it’s not full bore and/or you’re having vacuum leaks.

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Don’t forget micro cracks!

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my bigger recommendation is to invest in a wiped film evaporator


That’s a 5 figure investment.

Instead he can spend 900 on a new vacuum pump and 150 bucks on a tube of good vac grease.

  1. the lab society kit runs 10k on their website.
  2. people who run 5L stills can afford a wiper
  3. hes pulling 40 microns… is $900 worth of pump gonna change that?
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  1. No, it doesn’t.
  2. in what world does someone who affords a 12k system automatically afford an 80k system?
  3. Yes, $900 of the correct pump will fix that.