Short path distillation protocol for operating the genuine short path distillation systems for fractional distillation. We have been consulting on the short path distillation technique for several years. There is a lot of misinformation floating around on general extraction techniques & several others that will charge you for information that can be found here at Summit Research free of charge.

Short Path Distillation S.O.P. and the Operation of Fractional Distillation Hardware

Initial steps required for preparation:

  1. Winterization.
  2. Scrubbing and polishing.
  3. Removal of all solvent in evaporator.
  4. High temperature(140c) “punch” through all layers removing all water, alcohol, solvents, terpenes, etc..
  5. Pour into load flask.

It’s important to understand why we do not use a transfer fluid like alcohol anymore, this will create a very violent and unstable foaming and bubbling in the short path apparatus. To do this we typically place a large flask with 1.4 or less filled on a hot plate around 180-200c, this will heat up the large beaker. Allow stirring to be slow, and sometimes you need to apply hot air at top of beaker rim to facilitate the removal of solvents that would otherwise cool rapidly, re-condense and drop back into solution. This process leaves the solution very foamy, this is why we blow hot air on the beaker rim to rip out vapor via thermal CFM push with a spark proof heat source. Do not allow surface temperature to exceed 125-140c. We typically pull the beaker at right around 130c. At these temps, slight decarboxylation (decarb) occurs until you reach 150c, this process doesn’t take much time at all. If you load too much fluid in beaker this will rapidly foam and possibly run over the top of the rim. Once you have removed all the volatiles, now you should have a properly loaded up flask to begin the process.

The next steps are incredibly important to start short path distillation setups.

  1. make sure pump has been ran, oil has been changed and depth is verifiable with a meter or sorts.  this is a opportunity to do a service. if issues arise run pump under vac for about 1 hour to allow to heat up. replace oil, then run again for 30 min.  replace oil again. this double flush process should refresh your vacuum pump.  if this is not the case and your pump is having issues please get a new one and overhaul your current pump.
  2. clean all glass joints as if you were to perform surgery.  everything from colt trap, to short path distillation, even clean your lines if need be; replace lines if need be.  also make sure controller is clean and free from components lining inside.
  3. be careful not to use any hose laden with solvents or distillate as this will affect vacuum quality and performance.
  4. start assembling the glassware.
    A.   apply a thing film of high temperature ptfe vacuum grease. this rating must be beyond 4-6 scale at 280-300c minimum for distillation protocols to be followed.  the result in ignoring this will be chasing ghost leaks all over your machine and affecting your process.
    B.   the centered port on the Summit Research Triple offset flask is the thermo port.
    C.   the offset port on the Summit Research Triple offset flask is the short path distillation head location port.
    D.   apply grease on thermometer o-ring. tighten down, do not go over tight and ruin the material memory (under heat it will warm and smash on itself if you over tighten this part)
    E.   insert the 14/20 head plug (or key or key well) at top of spd head.
    F.   position head so base of head is 100% even and upright.
    G.   connect the monocow with a initial flask (250ml) for initial head fractions. at this time you should have another flask (500ml) attached to the second cow you were supplied in the set.  this second cow is the one that is spotless, and clean, readily assembled for the rapid swap that you will do.
    H.   connect monocow gl14 port to lower port of cold trap (chemical duty high temp hose).
    I.   now connect cold trap to dv-1 (now dv-2) throttling valve.
    J.   lower section of dv-1 absent of valves goes to the vacuum pump.
  5. at this time you should begin to add dry ice/iso to the ct-1 cold trap. below the trap in a plastic container as well.


*PLEASE NOTE* This SOP pertains to a BASIC short path setup like the one pictured below. As setups increase in complexity, change protocol accordingly.


You are now assembled and setup to begin the process of distilling curatives!

Basic setup:

short path distillation

Intermediate setup:

2L setup

Expert setup:

SPD-8 Short Path Distillation Setup

LET’S GET STARTED! Turn on condenser heater/chiller and set to 40-65c, we like 40c on first pass.

Start up your vacuum system. Allow a small leak to enter system preventing any initial boil over. Allow pump to pump but do not hit full vacuum yet. Begin adjusting all joints. Take note to the physical attribute of how the grease creates a film between the joints and ensure during this process the film becomes even while turning the joints to establish a full bite. now turn heat and string on. Begin stirring action around 200rpm. Start heat at room temperature, and start bumping up between 10-20 degrees C at a time. It is note worthy that the slower you raise temps here the more stable the mantle will be. During room temp all the way up to 140c this is the time this will be the hardest rate of temperature increase. If you ramp too fast the mantle will not see the differential, and it will over energize the bowl. This may over shoot in temperature and should be avoided at all costs. Stability in mantles increases the more you use them and the fuzzy logic pid will gather data on heat and thermo probe information to calculate the accuracy and stability. The more you over shoot, the more the pid will learn this, and continue to do this. The less you over shoot, and the more stability you create from your process the more the mantle will learn this and continue to function on point.

As you are increasing temperature your leak will slowly be locked off. The observation of this process is merely the result of action if the flask. The more action and popping you get the more of a leak you need. Approximately between 80-120c you will see the flask contents reside as a flat liquid surface; at this point you can easily lock off the leak and begin direct vacuum control.

During this time you will notice if material is prepared correctly, you should see little to no fractions until 180-200c or past that. Don’t worry you don’t have a leak happening. This determination of lack of reactions all depends on your skill level in preparing fluids to avoid all other boiling points that are unwanted, and the removal of inactive compounds within your solution.

Even if you see some compounds popping in the vigoreux section, its not an issue. These are all unwanted components. This next step is optional. There are a few ways to perform this, we will start with the most basic way. You will observe your cold trap, once all dripping stops you have gone beyond the volatile stages. This means the trap is nearly unneeded in the process. We see a typical removal of the trap around 180-200c. This process is as follows :

  1. Allow process to continue. when you notice a switch is required then perform these steps.
    a. Turn off heat.
    b. Turn off spinner.
    c. Allow pump to run under vac for a minute or so (this will remove residual thermal energy from the mass)
    d. Kill the pump, and begin bleeding atmosphere/nitrogen to break vacuum depth with the dv-1 valve setup.
    e. Immediately remove upper port from ct-1 cold trap and now screw it directly on the cow.(this whole process takes about 4 seconds or so)
  2. Now that you have performed this swap, you turn vacuum on first, and slowly dial out of atmosphere with the dv-1 valve setup
  3. Dial in vacuum first, get to as deep as possible first while locked off, you may actually need to throttle the dv-1 valve setup.
  4. Now begin the stirring action.
  5. Turn heat back on. Notice, you should see temperatures ON POINT, or slightly below the set point. During the time heat is removed, the vacuum applied creates a cooling effect on the mass. If you took too much time to do this swap you have effectively allowed the thermal mass of the bowl to over energize (increase heat) the load flask. If this occurs turn heat off and just allow vacuum to run. If you are about 10c over for example running vacuum will take about 2-5 minutes to decrease 10c. If you went over 10c, kick yourself in the face, you probably messed up bad and took too long to do the cold trap bypass.

I feel its important to add here. Don’t just do this process. Setup your machine with water. Turn it on to a low temperature, use a diaphragm pump for this. Practice the monocow swap, or even the trap bypass. Just practice doing it all day. Pump on, heat on, stir on, and reverse, and repeat. Do this over and over until your swaps are GENUINELY short and efficient. Have a friend stand next to you for help. If you are taking minutes to do something that takes seconds you are going to have a bad time. Practice makes perfect.

Now that your cold trap is bypassed, you are at direct connection for the process. The only option here is to replace the cold trap with a NEW CLEAN trap with the LOCK OFF CAP, this will allow you to use a clean trap that has no fluids or sources for micro boiling effect that occurs under high vacuum and depletes the vacuum quality affecting evaporation in load flask.

Now that you are at temp and vacuum begin to increase temperatures until you see your main curative body start to evaporate and saturate the head. We would suggest to allow full saturation to the top of the head to occur at this stage, the efficiency of this reaction in the e-vigoreux engineered pathway will allow all the clean compounds to flush out the pathway where the stinky and disgusting terpschwitz odors are laden. You should see a sequenced WAVE like effect at the top of the condenser entry point. This will fluctuate in effect but you’ll see the hot distillate flush out the entire pathway, sometimes spitting chunks of nasty terpschwitz compounds out into the first cow/flask.

Now you will repeat the swap process, only this time you will swap out the good clean rebuilt flask/mono cow assembly. Start simply by…

  1. Turn heat and stir off.
  2. Allow vacuum to dissipate energy in evaporation (subsided reaction)
  3. Break vac, replace mono swap cow assembly.
  4. Turn on vacuum, re-initiate reaction in neck.
  5. Dial in vig section as desired for purpose of distillation result (slow or fast).
  6. Begin string, this will create more violent reaction, use throttling valve to dial it in.
  7. Turn heat back on, if you are gathering a healthy fraction and set temp is higher than current temp, reduce set temp to right above 1c from current temp.
  8. Begin collecting the main body and regulate machine with temperature and vacuum pressures as need be. Increase temps only slightly to garner different vapor pressures to evaporate your main body. This is a very variable set points. It changes with a lot of material.

The above process can be bypassed with these different options:

  1. Swing arms
  2. Valved arms
  3. Discharge pump

You are now collecting your first pass main body. The rpm from starting at 200, can be increased as the mass of fluids decrease. More fluid requires less rpm, as fluid (distillation occurs and output discharge equals less load rate) becomes lower the rpm can increase. We have seen users go anywhere from 400-1800 rpm, however we like to see it around 400-900 typically.

Main body fraction collecting in flask(pictured) Main body fraction collecting in flask.

Imagine the main body from start to finish (no vapor pressure), now imagine there will be a 2/3 marker for the tails switch.

What this means, is you will be collecting the main body, fast or slow, however approx. 2/3 to 3/4 of the way in, you will see a obvious color change. This means you past your hearts section and dove right into tails. This is where odors and switching is difficult to control, you should have done the last switch PRIOR to seeing this color. You will have the tails resemble a darker scorched honey like consistency, this will literally coat the glassware inside. Normal clear is more volatile and purer, it will strip the glass itself leaving a pristine no tint visual observation on the glass. When the tails come you will visually see a tinted effect. We always switch about 3 or 4 minutes prior to seeing this. An explanation of what is happening here is the main body may be at 90-96% distillation output potency from the short path distillation systems. When this body comes it will itself be degrading in potency rapidly. When you see it it may be 88%, and within 2 minutes its spitting 40-60% potency rates. This is why your hearts is to be collected to retain the high potency rating. The tails to be collected later for reprocessing with other tails.

How is this done? same way….kill heat, kill stir, kill vac, break vac…NOW ONLY SWAP THE BALL, leave existing mono cow attached. now re-initiate your process and begin collecting tails. You can immediately crank temps up now and push out remainder of the product. There is no need to go slow slow for this process. This is just to gather remainder for future polishing and processing.