250 ml SPD, set up info etc.

Hey guys Im new to the extraction thing. I have made some qwiso extractions but had nothing to distill etc. so I just evaporated everything in a crystalizing dish.
As I am working as an chemical progress technician i know pretty much about the theoretic but haven’t really done it in person. I’ve only distilled some isopropyl and ethanol to clean it.
So now I’m about to buy myself a little distillation column with a 250 ml 3 neck boiling flask. Into the side necks, I will put a vacuum gauge and a thermometer. I think it’s the best to have the gauge straight to the flask do you guys agree with that?

On top of the flask, i will put a 100mm vigreux column with a thermometer for head temp and a short Liebig condenser leading into a distillation distributor according to Bredt. I have 4 receiving flask. I don`t know how much volume should I take because I also don’t know how much crude I should take for the 250ml flask. I’m very curious about the quantities.
I also bought a two-stage vacc pump from bvv with 4CFM.
The liebig cooler is only running with cold water, do you think this is to less?
When I have distilled the Iso and Ethanol I only used water and that worked out well.
And I also haven’t used my vacc pump yet the last time I only had a waterjet pump which was not working to bad.

(The iso and ethanol got distilled witch a cheap distillation column from china. Only a flask witch Liebig condenser into a receiving flask.)

So the general questions now are:
-Should this set up work for distillation?
-Does it have an appropriate volume?
-How much vacc should I pull? (I’ve already read a lot on the site but I’m not sure because all sops etc I’ve read already used bigger flask so is there a difference with the vapor pressure etc)
-do you winterize your distillate or is this just necessary at a diamond or terp sauce?

Thanks for your help and sorry if I wrote something wrong but English is not my main language :wink:

Dealing with volume of the product to be ptocessed, you can count maximum 50% of the volume of your boiling flask. That mean about 125 ml maximum.

Dealing with conditions, you should start doing some pre test using a SOP designed for small flask (1-5 litters), and then tune it to your system.


If I’m picturing your intended rig correctly it sounds like you’re trying to set up a still that’s more intended for fractional distillation of lighter volatiles rather than cannabinoids. Vigreux columns 100mm and up are generally used for creating a fair amount of reflux when separating lower boiling point compounds close in BP, you’re in the right ballpark with a short leibig condenser though.

This may work to strip terpenes from your crude, but may not be suitable for an efficient cannabinoid distillation. I would also reccomend doing at least a 2L set up and fit it with a proper SPD head, the returns you’re going to get on a 250mL system are probably not worth the time and money, buy one a little bigger and save up your crude to do at least 500mL. At least that’s my advice.

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Thanks for the quick reply.
I just already have a heat mantel for a 250ml flask and i dont really want to make a lot just to get to know the basics. Im in my apprenticeship right now and as soon as i am finished i would love to have my own little company doing growing, extraction and distillation… so maybe you can imagine better why only want such a small one.

So i will let the vigreux away and go with a normal spd.

Thanks again for your info!

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Most SPD heads you will find that meet your needs are either going to have a small portion of vigreux indentations in the bottom portion towards the joint that meets the boiling flask, or you may find a packable head.

It is useful to increase the number of theoretical stages and reflux to an extent in cannabinoid distillation, but you have to consider the properties of the compounds you’re separating. Watch a few videos online of cannabis spd and you’ll possibly see what I’m talking about. You should be able to find what you need for fairly cheap in 24/40 joints on ebay used.

If that’s all you have then do what you can, make sure your mantle has a stirring function or you will need either an overhead stirrer or a separate magnetic stirrer to put under your mantle.


I have a 250 ml spd setup I bought to mess around with, it’s a great learning tool. I run my rig with a Welch 1402, that 4cfm pump is a lot overkill for a 250ml setup, especially if your just learning Imho, 4-1 is a good rule of thumb, remember unless your system is full bore your going to be limited to your smallest restriction for molecular flow. I’d also be weary of putting your gauge on your boiling flask, you don’t want to contaminate it.

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Thanks for the answer!
Does the mantle need a stirring function or do you think it will also work with boiling stones?

Cool thanks! Good to know that it is working with this size.
Yeah i bought the 4cfm pump for my extractor and for purging shatter so i thought maybe it will work here aswell.
Do you know those water jet pumps you connenct to a normal water pipe from your house?
I have distilled some isopropyl alcohol with this and yeah i dont know how much vacc pulled because i had no gauge to measure. But the boiling point went from 82C to 67C.
So i dont know if this is just theoretical but i think this might work

X= 67Cx1013hpa/82C
X= 827,69hpa

Can i calculate this like this or is there any rule i forgot about or something i made wrong?


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Ok thanks, so for my understanding. If i want to destill 2 solvents with BP e.g 50C and 55C i would better go with a longer column because the boiling points are so close together and due to the column they get more „seperated“
And with the terps thc and cbd the BP span is bigger so its easier to seperate and i dont need a long column?

A water aspiration will not pull nearly hard enough to get the vacuum level you will be looking for. You need a two stage pump minimum. Don’t forget to flush your oil a couple times if you do decide to use that 4cfm pump, especially if you’ve been using it to purge extracts, the terpenes in the oil will fuck with your vac levels.

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What do you mean with flush? like winterize ?

No, I mean replace your pump oil.