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.