Post Distillation Odor

So my distillate is coming out quite pretty but with a fairly horrible odor. I know that there are a few ways that I can do remediation but I was hoping that there might be some pointers on how to minimize.

I believe it to be phytols from the chlorophyll breakdown, am I missing something?

Thanks for any help.



Are you using a short path to distill and how much volume are you distilling?


What’s your vacuum depth at?

B/r spinning band and the last run was 1.5 liters. Vacuum has been a battle on the still. So .07-.08 torr has been my best.

How hot are you getting your temperatures up to and how long are your runs?


the runs are taking way to long. Not sure what I am doing wrong but getting to heat takes a couple hours and pulling a liter takes 2-3 hours.

Temps top at 225 C in the pot. WHich is probably way to high but my automation is not in place yet.

You play with the little switch on top yet? @BR-Instrument should be able to chime in

do you mean the rotation speed of the band? Otherwise I use the fine and coarse knobs for vacuum adjustment regularly.

You can just reboil to about 150 or 180C under vacuum to get rid of most of the stank.

I find that when I take my time around 180C on my first pass that there usually isn’t much oder to remove.


thanks! you just re-enforced my instincts on the vacuum oven. I was thinking of running an N2 purge in and then using low temps ~70C over a longer period of time to avoid oxidation.

Is that 180 C in the pot or at the column head?

I just do it on the pot.

I know many people hate on OSS, but I have learned a lot from them; in person and in videos.

Here is where they talk about just re-boiling instead of doing a full 2nd pass. For some reason they call it a “2nd pass” but it never makes it over the head, so it’s not really 2nd pass distillate. Just 1st pass with a re-boil to remove the stank.

This, for the most part, works.


What are your condenser temps set at? Both the top and path?
Also how quickly do you pop THC, do you keep increasing mantle temps with the head temps automatically?

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If you are having trouble with vacuum there are some steps you can take to test options.

  1. Make sure system is clean and dry
  2. Check/change pump oil because of terpenes
  3. Check all clamps and gaskets. Gaskets, especially those exposes to heat, do need to be replaced. Also make sure one of the O-rings isn’t rolled. They have seams that need to be lined up.
  4. Pull down vacuum as far as possible.

If after step 4 you are still having trouble, send an email to Mark at, he will be able to send you a document containing more detail about sequentially finding a vacuum leak. I hope this helps a little!

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Just read your post concerning reboiling smelly first pass distillate under vacuum to remove smell. Very interesting.

Recently did my first SPD run and think that I switched to early from heads to main and therefore ended up with a smelly first pass end product.

I was thinking to go the heptane/c bleach route with a 2nd Pass followed but since color is already good I would prefer an „easier“ solution.

Curious if I could just place the half full receiving flask in a vacuum oven?

Also curious, how u choose the best Temp for smell removal?

How reliable is the method in removing smell? Are there any „smell scenarios“ where the method won’t work.

Thank u very much in advance & kind regards,


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Generally you can just run a second pass to clean that up as long as you pay attention to your fractions. Most of that should come off in the head and the rest in the tails. Your main body shouldn’t have much of a smell to it really. If you’re worried about compromising your THC just remember that residence time matters along with the PH of your source material. Your second pass should have as low a vacuum as possible so you can run at the lowest temps available to you.


Just do a 2nd pass, it should clean up the smell if you have removed all the heads. I usually just wait until the oil is dripping clear and then wait for like 10 to 20 grams, then flip to the next flask.

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What about running the hot head fluid tek? I forgot what called.

Shouldnt that help negate any odors?

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Breaking Dabs?

I can only get my condensor to 115C.

Hot condenser tec?

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I run my head with no fluid to get up to those 150c temps that are recommended