The biggest benefit to CLS over open blasting is safety. Operating a CLS safely requires close adherence to procedure and understanding the system you’re working with. This guide is made to introduce you to the procedure. Familiarize yourself with each of the components and learn each of the names, as they will be used throughout the guide.

Final image - component labels

Component Number Component Abbreviation
1 Extraction Column Valve ECV
2 Low Pressure Recovery Manifold RM (2)
3 High Pressure Recovery Manifold RM (3)
4 Purge Port PP
5 Recovery Cylinder RC
6 Vacuum Pump VP
7 Recovery Pump RP
8 Dehydration Column or Filter Drier DC
9 Extraction Column EC
10 Extractor Collection Chamber ECC


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

BHO-tard. noun. A person making butane hash oil that is aware of the following mistakes, but does not heed the warning:

  1. Blasting indoors
  2. Placing butane containers in the freezer
  3. Open blasting onto electric griddles
  4. Purging over an open flame
  5. Ignoring static electricity

BHOtard is a derogatory term. There’s no need to belittle people who make mistakes, but if they were aware of the consequences of their actions and ignored them, they might just be a BHOtard. Should something go wrong, the consequences could include potential death, 3rd degree burns, and multiple felonies.

Here are 57 pages of the icmag BHOtards thread. There are some common recurring themes in the thread and in the news. Here they are:

Blasting indoors.

This breaks the golden rule of hash oil extractions. Under no circumstance should anyone ever blast indoors. It is not safe. Under no circumstance should anyone ever blast indoors. It is not safe. Under no circumstance should anyone ever blast indoors. It is not safe.

A common element to all extraction disasters cited in the news is that people were blasting indoors. This is inexcusable. There is no reason to do this. It is unsafe. Butane molecules like to stick together and have a tendency to clump into a pool. It has a higher density than air, and therefore will fall to the ground waiting for the ignition source to spark a disaster.

Butane is relatively odorless and invisible – i.e. you can’t detect it with your 5 senses. There isn’t a safe way to get it out of an enclosed space if it accumulates. There are multiple ignition sources indoors. This makes blasting indoors extremely unsafe, even if you could sense butane’s accumulation.

Simply put, you put the lives of others in danger by blasting indoors. If that doesn’t compel you, your insurance policy will not cover such residential “manufacturing practices” – i.e. you are liable for any damages you incur, including bodily injury. DO NOT BLAST INDOORS!

Butane in the freezer.

Some open blasters try to replicate the process of making live resin by freezing their butane in freezers. This is a very bad idea. Numerous stories show that butane has the capacity to leak out from the butane can, fill the freezer with gaseous butane, and find an ignition source. This is similar to putting a bottle of soda in the freezer – it expands and explodes!

What happens is that part of the butane can is in the gas phase and the majority is in the liquid phase. Shake up a can of butane to prove it to yourself. There is a maximum allowable fill capacity for these containers. When they’re frozen, it increases the amount of liquid butane in the can. When butane in the gas phase turns to liquid, the liquid takes up more space than the gas. That liquid causes the can to expand and leak butane.

While cooling butane in a closed loop system with a cooling coil can be done safely, it can not be done safely in the standard cans that are used to fill butane lighters. The containers were never made to do this safely. DO NOT freeze cans of butane – you put other people at risk of burns and death. If you can’t think about the sake of other people, consider that most people who cause such accidents receive a felony arson charge and lose their liberty, along with some burns.

There is no excuse and no good reason to freeze the butane, regardless of how fire the extract will be as a result of getting cold butane.

Electric griddles.

Plenty of YouTube videos show people performing open blasting directly onto pyrex dishes. While there is nothing inherently wrong with that, people make the mistake to blast directly onto these dishes while they sit on top of an electric griddle. It’s a very bad idea.

Blasting directly onto electric griddles is a problem because there is a high concentration of butane that is evaporating off the warm pyrex dish. Those evaporating clouds find their way to the power cord, where there is an electrical current, and the cloud ignites. Meanwhile, the person blasting is holding onto a glass or PVC tube that’s dripping with liquid butane with an open can of butane affixed to the top of the tube.

This leads to a situation where the person doing the blasting is exposing themselves to shrapnel from glass and metal. If you’re going to open blast, blast onto a pyrex dish over a hot water bath instead, and do it outdoors.

Open flame purging.

For fuck’s sake! Who would think to do this?!? Or rather not think about the consequences. Do they not think that lighter fluid is used to make flames when released in small amounts? Have they not imagined what a cloud of butane would do in comparison?!?

Some BHOtards, I mean people, have taken it a step past electric griddles – they use an open flame under a hot water bath, with that pyrex dish sitting on top. Under no circumstances should anyone ever have an open flame near butane. For the sake of your life, nothing that creates heat, electricity, or flame has any business near butane extractions.

Static electricity is real.

Although it’s not as prevalent as the other mentioned ignition sources, static electricity is real and can cause gaseous butane to ignite. It’s easily caused by synthetic clothes, where the fabric rubs against another charged surface. The synthetic garment can carry the charge and be discharged at the most inopportune moments. When static electricity discharges under the right concentrations of butane, it can ignite the butane.

Now I’m not suggesting that one needs to wear a static free jump suit that tethered and grounded, but I am saying wear something like cotton and leather soled shoes that won’t have the tendency to build up static.

Closed loop system disasters.

Closed loop extractors are a million times safer than open blasting. They contain the butane solvents rather than letting it escape into the atmosphere. Still, this is no excuse to blast indoors. Mistakes happen and all mechanical systems fail. There are a few wear items that every CLS operator needs to keep in mind.

The most common wear item is tri-clamp nuts. They repeatedly get torqued and removed. These cycles of wear reduce the ability of the nuts to hold a tight seal. They are wear items and every CLS should have a good supply of them on hand and replace them when the threads wear out.

The second most common wear item are tri-clamp gaskets. Just like the nuts, they get repeated cycles of wear from the force of being clamped down. These too should be in the spare parts box of your CLS.

The NPT flare fittings that secure your stainless steel braided hoses wear out over time. This occurs on both Stainless Steel Hoses and on the male side of the threads that are on the extractor and recovery pump. They wear out at a slower rate than nuts and gaskets, but you should still keep an eye on them and inspect from time to time.


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

I remember the first time I transferred oil from the collection chamber of a BHOGart onto a silicon mat. Suffice it to say, it was a sticky shit show. Years of laboratory experience dealing with proteins that took months to purify have surely equipped me with proper handling techniques of some BHO, I thought to myself. Nope. It was terrible. I’ve since changed up my methods and added winterization to my routine. This makes for an easier process since you’re going to dissolve your extract in ethanol.

Speaking of lab experience, I would like to share one of my biggest lessons in the practice of laboratory science: DO NOT RUSH! Every time I’ve rushed an experiment, something went wrong. This is especially true for pharmaceutical products that humans will consume. There can be no deviations from protocol – this is the future of the cannabis industry. Extracts are difficult to deal with so don’t rush.

One of the key lessons from the laboratory is to have everything in place before you attempt to perform any process. This also applies to cooking – there is a French culinary saying, “mise en place.” This translates to “putting in place,” or having everything you need set up and ready to be used. This helps to prevent mishaps in the process.

Step 1:  read the post about winterization.

In that post I describe the ratio of ethanol to extract to best dissolve into, how to freeze and precipitate waxes from your extract, filtration/removal of the waxes, and how to purge off the ethanol. Assuming you’ve finished the initial purge of ethanol, you now have a soft pliable extract/ethanol mixture in your pyrex dish with a consistency/viscosity that is between molasses and honey. You’re ready for the scrape.

Step 2: transfer small sections of the extract from pyrex to oil slick sheets.

Again, take your time and be patient. Divide your extract into 8-10 segments and focus on transferring one segment at a time. Scrape underneath and gather the extract onto the top side of your spatula (or razor blade). It’s more important to transfer it in globs than it is for it to peel back as a flat piece – that happens after the final purge. This is a messy process and it never looks pretty until you get to the end product.

Place your silicon mat underneath your oil slick pad so that you know how much space you have to work with. Equally space out the globs from one another on the oil slick sheet and try to make sure that when they’re flattened out, that they will not take up a larger space than your silicone mat.

Step 3: sandwich your extract between the oil slick sheet and silicone mat.

Now that your extract is on the oil slick sheet, take your silicone mat that was underneath it and place it on top of the extract. Now flip it like a pancake, leaving the silicone mat on the bottom and oil slick sheet on top. You’re now ready to roll out the globs into a flat sheet.

Hot and cold conditions will help you manipulate your extract, but since it’s still in a semi-liquid form, the extract can still be manipulated. Take your rolling pin (just like the one Grandma uses in the kitchen) and flatten out the globs. You can work the globs towards the center of the silicone/oil slick sandwich and then work them back out towards the sides until you have an even layer of oil.

Step 4: peel back the oil slick sheet to transfer the extract to the silicone mat.

This is a tricky step to get right, and I will typically chill the extract in the freezer for a few minutes to make the transfer easier. The tool that helps this process is a ruler or straightedge. The mechanism/trick here is that the silicone mat will have more adhesion to the extract than the oil slick sheet will.

Now take your ruler and place it at one corner of the oil slick sheet. Pick up the corner of the sheet with one hand and start pulling it back over the ruler. The goal is to pull the corner you start at towards the opposite corner of the oil slick sheet. If all goes well, you’ll have a clean sheet of oil slick and all the extract will be neatly transferred to the silicone mat.

Things seldom go as planned. You will certainly become frustrated, but you must practice patience until you’ve mastered this process. Take your clean spatula if you have trouble separating the oil slick sheet from the extract, and help it along. Use your left hand to hold the ruler and the peeled back oil slick sheet, and use your right hand to manipulate the extract with the spatula. Again – take your time. Use cold conditions to help reduce the adhesion to the oil slick sheet.

You’re now ready to start purging.

Conclusion – take your time to master the skill.

Transferring extracts is sticky business. You will need time to refine your skill with the tools you have on hand. Perhaps you’ll invent a process that can be monetized! Know that with practice, you will master it. The fortunate part of this process is that you can always redissolve your extract with ethanol and start over.


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

Effective purging is dependent on three things – temperature, surface area, and pressure.

The right combination of these parameters will remove butane from the extract and leave you with a translucent slab of high quality oil. The wrong combination will leave you with a sticky mess that’s destined for a burn pile in your backyard.

To preserve terpenes, the lower the temperature, the better.

Butane and terpenes are some of the first molecules to evaporate while purging. An important point on purging temperatures: vacuum oven temperature may not translate to oil temperature. This is a point that is easily forgotten, and can be the difference between a product that shatters versus a pull-and-snap consistency. Check the temperatures of your oil with an infra-red thermometer.

There are several ways of removing the butane while retaining terpenes.

Keep in mind the boiling point of butane – it’s -0.5C/32.5F. If you purge long enough at room temperature at full vacuum, you will boil off all the butane – that process can take up to 5 days. Alternatively, you can increase temperature on your vacuum oven until the oil reads a steady 46C/115F, then pull a full vacuum.

Spread the extract as thin as possible so that the butane is exposed to the surface and boils off with minimal effort.

Surface area is the next big point in extractions. You need to spread the extract as thin as possible so that the butane is exposed to the surface and boils off with minimal effort. If you have the extract pooled up in a small container, it will eventually fully purge, but at geological time scales. This is best done with a two step process of pouring out the bulk of the extract onto one silicon mat and scraping out the residual extract with a spatula followed by spreading it onto a second silicon mat. This process minimizes auto buttering of the poured batch and requires the least amount of handling.

Cycle your vacuum on periodically.

Vacuum cycling is the next issue: cycle your vacuum on and off every 60 minutes, and keep it on for at least 10 minutes. Whenever there is a vacuum on the chamber, the extract is off-gassing butane, terpenes, and any other volatile molecules. If you pull vacuum on the chamber, but then shut off the pump, the chamber will fill with butane. Without getting too technical about the partial pressures of gasses, the butane gas in the chamber affects the rate of evaporation from the extract; it’s like having a room filled with balloons – if you’ve filled up the room, you can’t inflate more balloons until you get rid of the ones occupying the space.


By controlling the purge temperature at the oil, increasing the surface area, and cycling your vacuum, you’ll be on your way to dialing in your strain’s preferred conditions for making exquisite extracts. Unfortunately not all strains behave the same, and you’ll have to adjust temperatures and the timing of your vacuum pulls accordingly.

Why winterization stabilizes hash oil extracts

Why winterize your extract? Stability.

Winterization removes impurities – specifically plant lipids and waxes. This is a very important step if you’re trying to make shatter because the lipids will soften up the extract, giving it a pull-and-snap consistency and increase the tendency to auto butter.

Who needs to winterize?

People go through great lengths on their butane extraction system to have in-line dewaxing (winterization). Even with in-line dewaxing, you will not get a fully dewaxed product. Not all extractors have this built in capability so the alternative is to winterize with ethanol – this is particularly true with CO2 extraction rigs, where high temperatures and pressures prevail. If you want to remove plant waxes, you either have to winterize in-line or do winterization after extraction.

Four steps to winterize.

The process is simple to do. Specialized equipment stops with a freezer and a simple laboratory funnel/filtration system. The process roughly looks like this: fully dissolve the extract in warm ethanol by stirring; freeze the extract for 36-48 hours; filter the extract; purge the extract of ethanol. Sounds simple right? This guide will try to help you along the way.

Step 1: dissolve your extract in a 10mL:1g (ethanol:extract) ratio.

First, it’s not blasphemous to use warm ethanol. My first job as chemist was rife with lessons in solubility. As you’ll see on the Wiki article, temperature is one of the few variables that can be easily controlled and used to make your life easier. The lowest terpene boiling point is Beta-Caryophyllene at 119C; that said, you’re well below that temperature to get your extract to dissolve. Anything over 30C and below 60C will serve your needs, but the lower the temperature to dissolve, the better.

Once your ethanol is warmed it can be used to dissolve your extract. Choosing the amount of ethanol used is up to you, but keep it simple with a 10mL to 1g ratio by weight of ethanol to extract. Simply put, for every 1g of extract, add 10mL of warm ethanol. Once you’ve added the ethanol, you can stir manually with a small lab spatula or put it on a stir plate with a stir bar until the extract is fully dissolved.

Step 2: freeze your extract/ethanol solution.

Now that you’ve suspended your extract in ethanol, it’s time to freeze it. The goal here is to make a solution that’s similar to an oil/vinegar salad dressing – we want the plant waxes to float on top. Think of the ethanol as the vinegar and the plant lipids/waxes as the oil. Now what may not seem intuitive is that the plant lipids/waxes dissolved into the warm ethanol. Remember how I said temperature was a key to solubility? It still is – now we’re just taking advantage of the fact that lipids/waxes have a much lower solubility in cold ethanol compared to warm ethanol.

To be very sure that all the plant lipids/waxes have precipitated out of the solution, you just need patience, or very cold temperatures. If you have dry ice on hand, you can precipitate the lipids/waxes in 1-2 hours. If you only have a standard freezer, you’ll need 36-48 hours to fully precipitate the lipids/waxes. You will know your extract is ready for the next step when you have a layer of lipids/waxes formed on top of the ethanol solution.

Step 3: filter the plant lipids/waxes.

The laboratory solution is to have a vacuum pump, Buchner funnel, and filter paper. That is my preferred method. If you’re low on funds, the standard method is to use a coffee filter and funnel, letting gravity do the work. Either way, an important step is to have your entire filtration setup at the same temperature as the extract/ethanol solution; that way you will prevent the lipids/waxes from going back into solution from coming into contact with a warm funnel and filter. Place your filtration set up in a zip-lock bag and in the freezer an hour before beginning to work. The zip lock bag helps prevent buildup of condensation while you’re getting ready to filter.

Once you have your filtration apparatus set up, wet your filter paper with cold ethanol and apply a slight vacuum. On top of you filter paper, place 1-2 coffee filters into the funnel so you can easily remove the waxes. Now you can SLOWLY start to pour your extract/ethanol solution onto the filter paper. You don’t want to pour the whole batch in at once because your coffee filter will get saturated in plant lipids/waxes. The wax buildup prevents your cold ethanol/extract solution to flow through the filter, and you’ll end up redissolving more waxes.

At the end of step 3, you will have a waxy substance that looks like cannabutter sitting on top of the coffee filter and a büchner funnel filled with a translucent amber oil of the highest purity. You’re almost home free to having a highly stable wax.

Step 4: purging off ethanol.

When we talk about purging, we’re talking about evaporation of solvents. Those solvents could be butane, and/or ethanol. Purging is an easy job when you have a vacuum and vacuum oven on hand. Ethanol boils off at 78.5C at atmospheric pressure. If you pull a full vacuum (assuming you can pull -28.5”Hg), it reduces ethanol’s boiling point to 12.8C, which is well below room temperature.

The question to ask next is, do you want to reclaim your alcohol, or do you want to evaporate it off? If you desire to reclaim, the process requires a distillation apparatus, which is out of the scope in this article. If you’re evaporating off the ethanol, the standard practice is to transfer the dewaxed extract into a pyrex baking dish over a water bath; cover the pyrex dish with cheesecloth so that dust particles aren’t falling into the extract.

Evaporate off the ethanol until the extract is still workable with a spatula, and is a consistency/viscosity that is between molasses and honey. Check out the post on how to handle an extract after winterization. That describes the process after winterization and the initial purge.


You’ve followed the four steps of winterization. You’ve removed plant lipids/waxes and now have an enriched/purified cannabinoid solution. The biggest benefit to this process is that you now have an extract that will more easily “crystallize,” or become a stable product. The fewer impurities left in the final product, the longer the extract can be stored without changing its appearance and texture. Whether you choose to perform in-line dewaxing or to perform dewaxing with ethanol as described here, you’re well on your way to making high quality extracts if you do either.


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

“Simplicity, simplicity, simplicity” said Henry David Thoreau…

In any process, it’s best to simplify it if you can. In any math class, you want to simplify your algebra before doing more complex math. This is a matter of time, efficiency, and of course money. What I’m proposing here is that people simplify and perhaps improve their extraction process.

No doubt, hydrocarbon extractions are a risky business. On the small scale, you anywhere up to 12 pounds of butane in-line to your extractor at any given time. That has a significant explosion potential – the endless news stories of people blowing up houses describe it well enough.

Since most extractors have dry ice on hand to freeze their plant material or to control temperatures of their butane, you can just as well use some of that dry ice to concentrate your trichomes. This may seem like more work on the front end, but it does save you work in the long run, and is also much safer since it means less time cycling butane through your extractor.

It’s a matter of concentration (i.e. density).

In my former life as a protein chemist, concentration was everything. Concentration is described by the number of Moles of any substance, divided by the the volume (or the amount of liquid) the substance is dissolved in. Concentration is a close cousin to density. For the sake of our discussion, we’ll talk in terms of density.

Density can be described as the amount of weight divided by the amount of space it takes up (i.e. volume) – e.g. pounds/gallon or kilograms/liter. Now imagine that you have 1 pound of buds, and that takes up a space of a 3”x36” column. A 3”x36” column has a volume approximately 0.7 gallons. This works out to be 1.4 pounds per gallon or 0.17 kilograms per liter.


Now take that same volume of buds and make dry ice hash with it. Your yields will vary depending on the strain, but you can expect anywhere from 15-25% yields. This will produce a much smaller volume of concentrated trichomes. You don’t have to do much math to understand that weight for weight, a column packed with trichomes has more cannabinoids and terpenes compared to a column packed with nugs or trim.

To further the point, the density of cannabinoids and terpenes is much higher in a pile of trichomes than is in a equally sized pile of nugs. The point is that by concentrating – ie increasing the cannabinoid and terpene content while decreasing the volume – you increase the efficiency of your extraction.

Your goal is to get the highest yield dry ice extraction as possible.

In this case, you don’t need to make perfect, connoisseur grade, bubble hash. The amount of plant matter picked up is insignificant to the process since it will be filtered out during extraction.

So you’ve just taken 1 pound of dried buds that takes up 0.7 gallons of space and turned it into what looks like a powder that weighs 0.15-0.25 pounds and takes up something like 0.1 gallons of space. This defines the verb “to concentrate” as known by a chemist – you’ve just simplified your algebra. Now you have a product that will likely fit into a 3”x6” column, and can be run through the extractor.

The great part about this method is that you can filter out the plant material with your filter plates. You end up with a fine oil that is rich in terpenes and cannabinoids while limiting the amount of waxes and other phytochemicals that would be extracted from plant material. This is a major increase in efficiency.

Materials and preparations for making dry ice hash.

Dry ice hash is relatively easy to make. The tools of the trade are a 220 micron bubble bag, dry ice, and a flat surface to shake it out onto. A simple way of doing this is setting up a 2 bucket system, where one bucket fits into another. The top bucket will have its bottom cut out, and the 220 micron bag slips over it. The second bucket, with it’s bottom intact, fits over the 220 micron bag that’s wrapped over the cut out bucket, and is where you collect the trichomes. Pull the bag tight over the cutout and tie off the string on the bag to keep it tight against the bucket.

Dry ice costs $1.25/pound from the local grocery store, so the material cost is relatively inexpensive. You can be generous with the dry ice. A 1:1 ratio of dry ice to buds is the higher end, and you can get by with less, but you may sacrifice yields. Freeze your buds for 48 hours in the freezer before hand. Alternatively, you can just as well let the dry ice freeze them.

Making dry ice hash.

Break up your dry ice into 1” chunks to increase the surface area coming into contact with the plant material. Place the 220 micron bag over the cut out bucket and then put your buds into the 220 micron bag along with the dry ice. Gently stir the buds around with the dry ice, place the lid on the bucket, and allow the mixture to sit for 10 minutes to freeze the the temperature of the dry ice. At most, full freshly cut buds resting in dry ice take 30 minutes to freeze.

After freezing, vigorously shake the bucket. Alternate between shaking it up and down and swirling it around. Periodically check the bottom of the second bucket to see the quality of the trichomes.

Extraction and fraction quality.

Are the trichomes at the bottom of your bucket a light amber/golden color? Or are the trichomes now mixed with pulverized plant material?

You will likely want to collect a few different fractions – head fractions to heart fractions to tail fractions, just like a moonshiner. Shake a few times and look in the bucket. You might want to keep the first fraction for full melt hash (head fractions). Then shake vigorously and take a few more fractions (heart fractions). Finally collect the last fraction that will have the most broken up plant material in it (tail fractions). Now you have a range of grades (i.e. piles of different quality), ranging from golden trichomes to trichomes mixed in with plant material that have a green tint – heads through hearts through tails.

You can repeat this process several times over to collect all your grades as different fractions, but from multiple batches of fresh materials. Then you can pool them together and use them for individual batches in your extractor. Normally you pack your column with buds. Dry ice hash, or trichomes, just get poured into a smaller column and run as normal.

The goal here is to improve efficiency.

Less time running butane solvent through your closed loop extractor is a very good thing. It takes attention to detail every moment it’s running. One slip up, and you may lose your product or your life. From a risk based approach, Hemp Hacker believes this to be the very “best practice” that one can immediately implement in their extraction process.

The butane extraction side of the process works just like a normal nug run, but with an additional concentration step. While it adds a step on the front end, it reduces multiple steps on the back end. The main difference is that you concentrate the trichomes with dry ice in the first place, then dissolve them with butane. On a nug run, you would just be dissolving trichomes from buds with butane, and then collecting the cannabinoids and terpenes as an oil; the caveat is that you will have to do many more nug runs than with a trichome run.

Benefits of a 2 step extraction process.

While you may have green (tail) fractions that aren’t suitable for connoisseur grade hash, the plant material contamination will be filtered out by the filter plates at the bottom of your extraction column. This process takes care of the number 1 problem hash connoisseurs complain of – lack of potency due to plant material contamination in dry ice hash. You get the best of both worlds. An opportunity to collect the highest grade dry ice hash fractions with little to no contamination, and you also get to perform an extraction on the fractions that are contaminated with plant material and filter it out, yielding a high quality reduced wax extract.

Controlling humidity and water content during extractions is an important component to making quality extracts. When water contaminates an extract, it increases its tendency to auto butter when making shatter. This translates to reduced stability of an extract and a shorter shelf life. The two step process eliminates the largest source of water – the plant materials. The dry ice freezes all the water in the plant material, be it fresh frozen or crispy dry nugs, and allows the frozen glandular stalks that support the trichomes to be sheared off. The sheared trichomes fall off though the 220 micron bag and you have majorly reduced a source of water contamination (i.e. the plant materials).


Using the two step process of dry ice hash extraction followed by butane extraction in a closed loop system is a drastic improvement of efficiency. It reduces the total number of runs required, the amount of butane that needs to be dehydrated, and the inherent risk of using butane and hydrocarbons as a solvent. Given those factors, turning your one step nug run extraction process into a two step nug to trichome process will greatly improve your efficiency and in turn, profits.


Concentration – the amount of something (in weight) in a given space (volume) – e.g. pounds/gallon, grams/milliliter.

Contamination – any impurity in product – e.g. plant cell wall debris, water in extracts.

Fractions – different grades of trichomes/hash depending on amount of plant material contamination.

Risk based approach – examining the inherent risks involved in a process and eliminating risks to improve the product safety or process safety.


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

There are probably a dozen different ways to pack a column. While as a Sergeant in the Marines, I was sometimes amazed by the different interpretations my Marines would take on what I thought to be a clear set of instructions… So it goes. Everyone has their own interpretation on how to do things.

The process of packing a column is no different – everyone can have their own interpretation. In my view, there are two “best practices” in order to pack a column. I’ll explain the two and you can choose what works best for you.

Either way, your goal is to reduce the amount of condensation on the buds and the inside of the column. Condensation is the enemy because it reduces the ability of butane to solvate the lipid/waxy bilayer of the trichome – in botany, that layer is called the cuticle. If the cuticle is surrounded by frozen water, the butane can’t penetrate and the extraction efficiency decreases along with your yields.

Temperature and time.

You’ll likely have two options for freezing your buds and column. I will assume that everyone who is doing extractions has, at a minimum, a freezer capable of maintaining 0C temperatures. In this case, you will need 36-48 hours to ensure that all water has been locked up in its solid phase as ice.

If you have dry ice on hand, which most live resin extractors do, you can pack your freezer with a bed of dry ice. When you freeze your buds and/or bud packed column on dry ice, you drastically speed up the freezing process. A thin layer of freshly picked buds packed into a vacuum sealing bag will be frozen in 30 minutes. If you’ve pack it into a column, give it 2 hours to ensure a full freeze.

Method 1: pack freshly cut buds into the column and freeze.

This is probably the easiest method. Simply cut the room temperature buds up into 1/2”-1” diameter. The column should also be at room temperature. Loosely pack the column with the buds. You’re now ready to freeze the column and buds. Once fully frozen, you can begin your extraction process by vacuuming out the extractor and column.

You should vacuum out your column only after you have frozen the buds. The reasoning is that vacuuming unfrozen buds will cause the plant cell walls to rupture, releasing the water and phytochemicals that you are trying to avoid extracting in the first place.

Method 2: freeze freshly cut buds and column separately, then pack the column.

This method is just as sound as the first. Again, this is a matter of preference, but has its own merits. Cut your buds down to 1/2”-1”. Pack them into a vacuum sealed bag and evacuate the bag – as in method 1, pulling full vacuum may rupture plant cell walls. In this case, a vacuum sealer will not develop the same pressure as the vacuum pump used to evacuate your extractor. That said, the biggest benefit of this method is being able to freeze larger quantities and store them in the freezer until you’re ready to extract them.

In the meantime, you will freeze your empty column until its temperature is the same as the frozen buds. In this situation, you want to pack your column quickly to prevent condensation to form on both the buds and the interior of the column wall. Ideally, you will have a room that has a very low relative humidity. Once packed, you’re on your way to assembling the column to the extractor and start to pull a vacuum.


If you have the tools of the trade on hand – ie a vacuum sealer and dry ice – I prefer method 2. If not, you will not be at a total loss to use method 1 and just freeze the plant matter in the column. If you have several columns on hand, you’re not at much of a loss. If you have one column on hand and no vacuum sealer, you can still get by with a modified version of method 2.


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

Setting up your recovery pump is a simple process on most extractors. You will likely have a 3/8” recovery hose connected to the lid of your collection chamber, where the gaseous butane is pulled through to the recovery pump (low pressure side) and pumps out to the high pressure side to be dumped into the recovery cylinder. 

A real world example by an awesome company.

There is a very good example of this setup on the market by Precision Extractors. If you pull up their website and take a look at the back of the extractor, you’ll see there is a column that is plumbed and placed behind the secondary recovery cylinder (on the right). That column is filled with 3A molecular sieves and is plumbed to the primary filling cylinder (on the left).

Their system works by pumping butane from the primary filling cylinder into the primary extraction column. After passing through the primary extraction column, it passes into the dewaxing column. The butane is evaporated off by heating the collection chamber and the negative pressure from the pump, pumping the butane into the recovery chamber.

From there, the butane passes through the pump in the gas phase to the 3A molecular sieve column. The butane gas passes out of the 3A molecular sieve column and is pumped into the primary filling cylinder where it condenses into the liquid phase due to the cold temperatures and higher pressure.

Although Precision Extractors have this set up natively on the PX1, there’s no reason a similar system can’t work with your current extractor. The explanation follows below.

Setting up your current extractor for in-line dehydration.

This is a simple system. It really just requires an additional column with end plates, an inline filter, and one additional stainless steel braided hose. Read up on the post about dehydrating your butane. On average, 1000g or 1Kg or 3A molecular sieves will be have enough capacity to dry all the butane you could use in a week. Use an appropriately sized column and pack it with the sieves. Connect a filter plate and a filter at the bottom of the column, and you’re nearly there.

Connect your 3A molecular sieve column (8) between the collection chamber (10) and the low pressure side of the recovery pump (7). While you may say that in-line filter driers can do the job, they’re not really up to the task when you do the desiccant math. This is a step that is better done with more desiccant than less. This is a simple improvement on what most people already do. You can certainly use an inline filter drier, but this ensures an efficacious dehydration.

Dehydration is an ongoing process.

While putting a column of molecular sieves inline is an improvement, it is only part of the process. It is very important that the molecular sieves are dried out after a day’s extractions. The nice part of this setup is that you can easily remove the molecular sieves from the column. That’s important because you need to dehydrate your sieves after you use them so  they’re ready to dehydrate your butane – the beauty of molecular sieves is that they are re-useable.

Once you’ve removed your sieves, pour them out into a pyrex dish. You can then put them into your vacuum chamber, apply heat and vacuum, and have fully recharged/dehydrated desiccant ready for use in the morning. This is a standard process in the pharmaceutical industry where drug substances must be kept free of humidity while in storage, and the molecular sieves are periodically recharged.


For the price, you can’t miss the beat on dehydrating your butane. Not only does the dehydration improve your yields, it also helps save the seals of your pump that do not react well with water. Given those two improvements, the small investment of molecular sieves in-line from your extraction chamber to the low pressure side of your pump will pay itself back quickly.


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

Water kills butane hash oil yields

Butane picks up water during extractions and causes lower yields.

Butane picks up 3.25mL of water per liter and propane picks up 3.9mL of water per liter. To put it simply, water in butane and propane takes up space that prevents cannabinoids and terpenes from being fully extracted. That’s a problem.

How does water contaminate extractions?

Water contaminates extractions because of its effects on solubility – water in your butane and propane decreases the potential solubility of cannabinoids and terpenes, but it also picks up water soluble contaminants like plant chlorophyll, alkaloids, and flavonoids. If you’re looking for the simplest solution, just dehydrate your butane/propane. If you’re looking for perfection, purge your extractor with CO2.

Improve yields in 2 simple steps.

It’s all about the chemistry of inert conditions/reactions. There are two simple steps for high quality live resin extractions: 1. dehydrate your solvents; 2. purge your live plant materials and extractor with a dry gas like CO2. Putting together the steps of dehydrating your butane and purging your extractor will most certainly increase your yields, but it also functions to reduce contamination.

Dehydrating butane and propane is the most important step to improve yields in live resin and regular extractions.

Dehydrating your solvents is as easy as packing your extraction column with a substance such as 3A molecular sieves or activated alumina. Molecular sieves and activated alumina are used to dehydrate butane/propane in the gas phase – ie you do not pass liquid butane/propane through a column packed with these desiccants.

3A Molecular sieves are widely employed in the lab setting, where they’re used to dry solvents or keep solvents dried in the first place – they can hold up to 19-20% of their water weight. Molecular sieves are also FDA Approved for direct contact with consumable products. Activated alumina has a higher water capacity. It’s used in number of industrial drying applications for hydrocarbons, but there isn’t sufficient data proving its safety beyond “Satisfactory” compatibility with butane and propane.

Check out the post about recovery pump setup and see how to set up a system that will effectively dehydrate your butane and propane.

Desiccant math made easy.

You need to do little math to figure out how much space your molecular sieves will take up, and to figure out how many grams of molecular sieves you need. Molecular sieves cost approximately $100/500g, but they are nearly infinitely reusable. You can regenerate or dehydrate them by heating them up in a vacuum oven and pulling full vacuum. Here’s the math:

lbpergaltokgperliter (1)

Most extraction artists use US pounds to measure their butane, so we have to do a few conversions. Let’s say you have 12 pounds of butane. You need to convert it to kilograms, so you can take into account the density of butane (assume 1bar/14.5psi and 20C/67F); you use the density to convert the mass (i.e. weight) of the butane into a volume (liters). Now you can multiply the number of liters by the water:butane conversion factor to determine the amount of water that the 12 pounds of butane can hold. Finally, multiply the amount of water in your butane by the water capacity of the molecular sieves. This shows you minimum number of milliliters or grams of molecular sieves you need to dehydrate your butane. That said, 675mL of molecular sieves weighs approximately 1000g. Buy two 500g containers and you’re home free.


Dehydrating your butane is a step forward in improving your extractions. Not only does water in butane decrease extraction efficiency, but it also causes increases the extraction of plant contaminants like chlorophyll, alkaloids, and flavonoids. If you’re looking for perfection, you’re going to run your extractor like an organic chemist synthesizing a compound under inert conditions. You’re drying off all the water from the extractor walls with a hot air gun, then you’re pumping out the water trapped in the atmosphere by pulling a full vacuum. These steps make for a higher quality and more consistent product.


Thermodynamic properties of butane and propane:



Activated alumina:



Molecular sieves:



As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.

This is how a chemist makes live resin, attending to every detail. Sometimes the additional work is well worth the reward. Every person running an extractor is a scientist in one way or another. Over time, you test things, figure out what works, and you have the best possible product. If you are looking to maximize the quality of your extracts, consider these points.

Inert conditions are important for humidity control.

The amount of humidity in the air is dependent on where you live – Denver is generally dry, whereas Seattle is generally humid. If you’re in Seattle or any other humidity prone area, inert conditions are important to factor into making a high quality product. That starts with running a dehumidifier at full blast in the room that you’re preparing your fresh plant materials in.

Drying your inert gas.

Argon is the ultimate and preferred inert gas. Alternatively, everyone has access to CO2, and drying off CO2 is an easy process with anhydrous calcium chloride. Pack a small column with filters at either end and pass your CO2 gas through the column. This can be used directly in-line from your CO2 cylinder into your extractor as well as to purge the bags you’re freezing your plant material in.

Inert conditions in an extractor.

One of the first steps of performing a closed loop extraction is to vacuum out the extractor. There are a few reasons to do this. One reason is to remove as much air as possible in order to prevent a potential explosion from oxygen mixing with butane. The second reason is to create a vacuum in the closed loop system that will pull liquid butane into the extractor from the recovery tank. While pulling a vacuum on an extractor removes most of the air, water can still be left behind in a very thin layer – i.e. a monolayer.

Purging your extractor with inert gas or dried CO2 helps remove the water monolayer of condensation.

The purpose of purging your extractor is the same as the purging your bag filled with fresh plant material (see below) – you’re removing the ambient humidity that would otherwise condense on the walls of your extractor and contaminate your extract. Dried CO2 gas can be run through the extractor to help eliminate water.

Vacuum out your entire extraction system. Once vacuumed, fill the extractor with dried CO2 from an inlet port. Allow the extractor to completely fill up with the CO2. Allow a portion of the CO2 to escape the extractor, releasing more ambient humidity, then vacuum the extractor back down to it’s maximum vacuum. There are several ways to go about this process, and it really depends on the design of your extractor.

You can repeat this process, but in reality the first CO2 purge followed by pulling a vacuum on the extractor will take care of the remaining water that was in the atmosphere of the extractor.

Minimum standards for inert conditions and removing the water monolayer of condensation from your extractor.

I get it – purging with CO2 sounds like it adds a lot of work. The minimum standard to achieve inert conditions is quite simple: heat and dry off the interior of your extractor with a hot air gun (aka blow dryer). This dries off the monolayer of water that will have condensed onto the interior surface of the extractor. Once you’ve dried off all interior surfaces of the extractor, seal off the extractor, and purge to full vacuum. Close off all open ports to the extractor and allow it to cool down. Connect your column and begin your normal extraction procedure.

If you’re going the extra mile, complete the minimum standards described above, then fill the extractor with CO2, and pull another vacuum.

Purging live plant materials with dried CO2 prevents water condensation during freezing.

Purging live plant materials prior to freezing is mentioned in the temperature post here on Hemp Hacker, but it’s also touched on here. The reason for purging your fresh plant materials before freezing is that there is humidity in the air/atmosphere. That atmospheric humidity has a tendency to condense on the buds as they are freezing. Purging your freezer bags prior to freezing reduces this tendency.

Dried CO2 gas is ideal to purge with because it displaces the ambient air/humidity from the bag that’s used to freeze the plant materials. The trick is to make sure all humidity is out of the bag – about 3X the bag volume is a good amount, and you can be relatively sure that all the ambient humidity is purged out. Once purged, the bag can be vacuum sealed and frozen in a freezer, or even better and faster by submerging the bag in a dry ice/ethanol bath.


If you’re in to making the highest quality products, purge both your plant materials and your extractor with dried CO2 gas. These two steps reduce the amount of water in your starting materials and will reduce the tendency of auto buttering extract. In addition, it will improve the stability of your extract.


As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.