Short path and terp collection

Hi, new member and extractor here. I need some help on how to collect terps with the short path. I’m really happy with the quality of the oil I’m getting, but I was hoping collect the terps and add back to the distillate. So far, nothing in the heads flask smells usable and the cold trap is empty. Any ideas, or good reading material on the subject? Thanks


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Ur collecting too much of that fraction, heads will come after the terps. Ive only gotten terps once that smelled nice from a short path but i dont intentionaly collect the terps everytime

Thanks for the info. Are you saying to collect more fractions and the earlier ones might be useable?

Is it possible to re-distill the heads to pull out the terps?

If you set the glycol chiller to around -15° c and run the mantle around 33-43°c you will collect a pretty nice amount of terpenes without cooking them. Terpenes start to degrade and burn after 45° so slow and low temp is the way to go.


That’s good info. Thank you!

i would imagine a lot of good terpenes get evap’d off during roto then really get boiled off when decarbing. i know my etoh smells lovely after i recover it in the roto

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You’re probably right. I noticed the recovered solvent in the roto has a faint terp smell.

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i always get the sweet smelling terps in my etoh during recovery but when i get my buddy to run my crude in spd it smells like butthole.

maybe the trick is to capture the sweet smelling terps from the etoh during the cooler reclaim phase?


That might be doable with a really tall column and a very full boiling flask. I would try and figure out how to get the terps as early in the processing as u can, i think the terps change and degrade everytime they are “distilled” over. I would try what blacktooth said and make sure u also have a dry ice dewar condenser.


Thanks. I think what you’re saying is right. There is some vapor passing through/not captured at the start of the run. I’ll try circulating a dry ice bath on start up and see if I can catch them in a separate flask

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Thanks for the ideas everybody. Quick update: I did 2 experiments. 1st way, I packed the base of my cold trap with dry ice, full vac, set the mantle at 20C, then slowly increased to 40. When there was no more vapor rising, I stopped the run and dumped the contents of the cold trap in to a pitcher to allow the dry ice to sublimate. What was left in the bottom was terps. It smells like the strain it came from, but not fresh. I think I may have picked up some contaminates from the vac hose or the dry ice. I wouldn’t do this method again. The 2nd method, which I’m really happy with, was to allow the oil to get to 15C (so the stir bar will move freely), then turn on the vac. I had the condenser set at 30C hoping the vapor wouldn’t leave the condenser and get sucked out. I slowly raised the mantle temp to 45C, cut the vac, and was able to collect the terps from the heads flask.


It would be interesting to get this tested maybe gas chromatograph testing to see whatcha got

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Very true. I doubt that it’s a full spectrum because of the limited temp window I used. Def scared of getting the heads taint smell. Now that I know it’s possible, I can try pushing the temp up by a few degrees each time

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Has anyone used steam instillation to capture the essential oils first, before the ethanol wash. Then after SPD, adding the essential oil back?