Advanced short path distillation techniques have advanced tremendously for the curative industry.

It’s important to have a basic understanding of Advanced Short Path Distillation before diving into the advanced techniques. We suggest reading some of our previous articles on fractional distillation & engaging with some hands on experience to perfect operation of the equipment. This is information that we make openly available, while others may charge for consultations you can find a major resource here. This process was refined through benchmark testing with numerous skilled technicians.

Items needed for the filtration process:


For a diagram on how to set up the filtration system check out The Hochstrom High Flow Filter page. 

Mastering Winterization – Fat, Lipid, Wax Removal Process

This process of winterization was originally developed by Summit Research during our early stages of R&D. We’ve changed things up to improve efficiency compared to traditional winterization techniques. Here is the original Summit Research winterization technique :

  • Melt down your base starting material (oleoresin) at a 1:10 ratio with alcohol to create a “solution”.
  • Place the solution in a deep freezer. If it’s dry ice ice 30-60 minutes / if it’s in a cryo freezer this may take 2-4 hours.
  • Allow the solution to begin “waxing” up than remove from the freezer.
  • Leave the solution out to warm up, keeping it at least 20 degrees below room temp. This allows major components to precipitate from the solution.
  • Begin a large micron filtration, in our case we use a Hochstrom with a stage 1 (20 micron) chemical duty paper.

All filtration for dewaxing with hochstrom filter only need to be at half vacuum (about 350 Torr) for best flow. The addition of glass wool is highly recommended to buffer the fats and help speed the process up.


The pass of semi-cold fluids will now flow with improved efficiency. You will “rough cut” the solution & remove a major part of the mass, very fast in this case. It is due to the solution being at temperatures where it’s not frozen, yet still cold enough to maintain it’s property.

  • Then place the solution back in a deep freezer & allow it to winterize overnight / 12-24 hours
  • Wait for it to coagulate (“waxing”) again.
  • Once it begins to clump together remove the solution from the freezer.
  • Immediately begin the filtration process, we recommend the Hochstrom with a stage 2 (8 micron) chemical duty paper. Do not let the solution warm up, only pull out what you are planning on filtering at that moment.
  • If you feel the need to double check that you have removed all the fats and waxes place the fluid back in the deep freezer & allow it to winterize overnight / 12 hours again. Refilter the product and see if there are any more fats that are filtered out. If nothing clumps up & the solution is free of all coagulation you’re ready to move onto the next step.

See how the initial “rough cut” of the cloudy mass will flow faster due to different temperatures and separate passes. Even though your filtering twice your filtration time will still be less than if you did all this in one pass. 


If you need, you can repeat the last stage of winterization as needed until you see results. For further filtration consider a Stage 3 (1 micron filter). Winterization is essential to remove most of the unwanted compounds at different temperatures, allowing for more efficiency in the overall refinement. The winterization is essential to do prior to this next step, or it just simply won’t work for erroneous reasons.

Carbon Scrubbing & Polishing Extracts

For this process you will need the Summit Carbon and the Summit Silica Pulver. The Summit Research Carbon Powder A is the most commonly used carbon and is extremely efficient in removing color, Chlorophyll and  any unwanted or inactive compounds. Using the Silica Pulver helps filter out the carbon and also allows the fluid to flow freely with very little restriction when filtering.


  • First Increase the temperature of the oil and alcohol solution to 100-120f (38-48C)` using the proper hardware & in a well ventilated environment. Once the alcohol is at temperature add the carbon & seal it off. You will gauge how much carbon you will put into the system to the amount of extract you have in the solution after winterization.


  • Example: 1,000g Starting Material – 30% winterization loss = 700g Winterized Rate + 3.5-10% carbon based on the quality of the starting material.


Once you have the carbon in the warmed ethyl and oil mixture, shake or mix vigorously for 5 to 15 minutes. After this you will prep the filter to remove the carbon.


  • Prepare a Silicate Pulver bed by pouring 500-600 ML of silica into a beaker and mixing it with about 500 ML of alcohol. After mixing the solution you should see an average volume of 600ML and the mixture should have the consistency of a melted milkshake.
  • Prep your Vacuum  depth so you are not pulling too hard and compress the silica bed, this will greatly slow the filtration process down. This part of the filtration process requires even less vacuum than needed for dewaxing with the Hochstrom filter, you will only need to pull ~500-600 torr for the vacuum. We recommend starting with 600 torr and then decreasing to 500 torr once you have started filtering.
  • Pour the Silica Pulver mixture into the hochstrom over the stage 3 papers without any vacuum being pulled yet. Get your carbon solution in hand and start the vacuum. You will start to notice the fluid level lower and the silica create an even bed. The moment right before the ethyl has sucked through the Silica bed you will want to pour the carbon mixture. At this point you will continue to filter until you really start to see the fluid slow down. You should be able to get about 20L’s of fluid through before it slows down too much for you to continue.


  • Some people will use a gloved hand or a clean spoon to pour on top of instead of pouring directly onto the silica. If you pour directly into the silica it can create a divot in the silica and could allow carbon through.
  • Once you initiate vacuum-
    • If you pour too early and the Silica bed has not set you will mix the carbon into the silica and it could get through the bed.
    • If you pour too late and the bed dries out you will get cracks in the bed and it will allow carbon through.
  • To check if any  carbon has gotten through look at the cake after you take the Hochstrom tube off. There will be a cloud of carbon on the bottom or you will be able to see the carbon creep down the sides of the silica.


Now you have a scrubbed solution and will want to do the following.

  • Roto evaporates out alcohol. Check out the rotovap instructions if you need instructions on how to rotovap.
  • When the fluid in the roto has clumped up and the extract has near zero alcohol you can either get ready to go into distillation or you can continue into a saline water wash.


Optional: Saline Water Wash

Items needed for the saline wash process:



If you are using a separatory funnel check out how to set it up here.

To continue into a saline wash:

  • Introduce hexane or cyclohexane and dissolve the solute into a new 1:1 hex solution ratio.
  • Using a separatory funnel or reactor, add the hexane solution (scrubbed oleoresin) into the separatory funnel. Your desired ratio will be at a 1:1 ratio of Hexane solution to saline water.
  • Take warm distilled water and add salt (1-7% salt to distilled water). Allow solution to cool but make sure it has been fully saturated with salt.
  • Separating the water into 3 parts, you will need to PH them to make sure your solution will stay as neutral as possible.
  • Use Summit’s special citric acid to bring one part of the pH saline solution to pH 4.
  • Use sodium bicarbonate to bring the second part of the pH saline solution to pH 8.
  • Add the pH 4 saline to reactor and mix for 10 minutes.
  • Drain the saline and repeat the same steps with the pH 8 saline solution.
  • Finally repeat with remaining third part of the neutral pH saline solution.
  • Repeat the process with the neutral saline water until saline water layer is clean. This can take 12-24 washes to see results depending on the quality of said product.

Wait what just happened here?

In winterizing & carbon scrubbing you only remove oil soluble compounds in a solvent layer. The similar boiling points to curatives that come out during distillation are water soluble compounds – what are these? These attribute to the color : yellow, orange, reds, etc. When washing with salt water you get a lot of stuff that water attracts while the oil stays in the hexane layer. This will help refine a clear distillate upwards to the first pass & beyond. More steps are to be taken if you want to show off colors. Always remember to do the following

  • Remove hexane in roto.
  • Remove all water, alcohol, terps, etc. so the solution is pure oleoresin that has been fully scrubbed and washed thoroughly.
  • Heat the fluid in the roto to about 75-80C to aid in transferring the fluid into the boiling flask.
  • Begin first pass at full temperature, full efficiency, and removal of the entire body in the shortest amount of time.

Collect this “first pass” distillate and if needed repeat the winterization process & another hexane, or pentane wash. In the second treatment we find the most color reduction and compound purity results prior to the second distillation or subsequent passes thereafter.

Now after the repeated winterization treatment of the processed oleoresin is complete, reload the machine and allow the Short Path Distillation (SPD) series unit to operate. In this short path distillation (SPD) process you will now achieve deeper vacuum rates, higher rejection rates in the E-Vigoreaux section as well as much higher purity results. This is usually done at a slower pace, allowing you to dial in how much rejection you want. The Summit Research unique process allows you to obtain high yields with just a single material treatment and a first pass. This is where numerous distillation techniques come into play to produce those desired guaranteed test results. We are positive you’re going to want to add this tool to your bag of tricks. This process allows the second, third, etc passes to be done at a faster pace, while the material dwells in lower temperatures and therefore, unaffected. High separation processes at higher initial first pass temps causes many more issues. Resulting in the refined and precise protocols where we have created a minimal chance in high temperature exposure times.

Be sure to look at an older SPD post on techniques (12/2016)