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QWET oil extraction

Gray Wolf

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QWISO and QWISO, as well as QWME often get lumped under the title of QWISO, even though there is significant differences in the three alcohols.

Here is the student hand out detailing how we extract oil at the pharm using 190 proof ethanol alcohol and decarboxylate it for oral consumption.



QWET OIL EXTRACTION


Quick Wash Ethanol, also know as QWET is one of the techniques commonly employed to extract oil from cannabis.

Here is skunk pharm’s QWET formula to produce an absolute using a 3 minute quick wash.

As most of our extracted oil goes into oral meds, we also decarboxylate ours. This process is based on the 252F curve shown in the attached graph; I copied from Jump 117 in Moscow.

The first question is why use a quick wash technique to extract the resins, instead of long soaks to extract as much resin as possible, or just boiling the material in alcohol to get the greatest amount of extracted material?

The answer to that is that because alcohol is a highly polar solvent that is soluble in water, the latter two techniques also extract the water solubles like chlorophyll and plant alkaloids, as well as the plant waxes and vegetable oil.

Even quick wash does to a lesser degree, but the added steps that we include here minimize pickup even further and we take additional steps to remove the impurities that we do pick up.

The first wash will usually extract 75 to 80%, leaving the balance for the second. The second extraction will be more sedative and less heady. If you use a hand microscope, you can easily see when the trichome heads are gone and the stalks look like wet fur.

You can also use the material for other extraction methods after it has dried. I have subsequently used BHO after the first QWET wash that yielded 16% oil by weight, and got 5% more pristine oil, or about 21% total.

A cured material QWET absolute is one of the most aromatic and tasty of the extraction methods and consistently gets high raves from the volunteer test panels, as well as the patients and students. Both from an efficacy, as well as a flavor standpoint.

The first step in the process is to get as much water as possible out of the material.

A fresh material QWET is possible, but this procedure is specifically for material that has been cured to about 15% water content, which is typical of cured material. 15% is a lot of water and the alcohol already has 5% in it, so unless we reduce the water content even further, we will be extracting a lot of water solubles.

We dry our cured material even further by spreading it on a cookie sheet and baking it in a 200F oven until just frangible when rolled between the finger and thumb. Just frangible does not mean powder dry and still has some moisture content that we will control by freezing. If the material is too dry and frangible, it will break up and add color.

We then scrub it through a coarse wire mesh pasta strainer, using a leather gloved hand and firm pressure, so as to minimize the amount of fine particles generated. We never, ever, use a food processor or blender, as it creates a large amount of fines.

The stems will be left behind, which I encourage you to save for a different extraction, and make a killer topical out of them. If you leave them in the extraction, they will leave some of their flavor behind.

We never, ever, use a blender or coffee grinder to reduce material, because it produces a lot of ultra fine powder that makes it through conventional filters.

Next, while it is still warm, we seal the material in a jar, which we place in the freezer to tie up any remaining water as ice. We also put the 190 proof grain alcohol in the freezer.

When they have both stabilized at about 0F, pour the alcohol into the jar of plant material, so that it is at least an inch above the material, and shake it gently a few times to make sure everything is wet. Place back in the freezer.

Remove and gently shake twice more until the material has soaked for 3 minutes, and then dump it through a wire strainer to drain quickly.

Set the material aside to dry for a second extraction. We usually keep the two extractions separate, as they will have different properties.

Filter the extracted liquid.

We use either a vacuum filter or a simple coffee filter, depending on the quantity we are processing.

Place that filtered liquid in a suitable container and set that container in an oil bath heated to 240/250F. We use bain marie and other stainless ware from a restaurant supply.

Make sure that the container is sitting on something that suspends it up off the bottom of the oil pot. I throw four jar lids in the bottom of my electric fondue pot and use it for that purpose.

Never trust the numbers on the dial and use a good thermometer to set temperatures. We use either a mercury lab thermometer, or a digital one. Good temperature control is key to the process.

That means the device that you use to control the oil temperature must have a narrow dead band, so that the temperature control is stable.

I paid about $60 for a Quisinart fondue pot that was designed to heat sensitive sauces like chocolate and has excellent control throughout its temperature range. There are a couple of Revels in our group that are slightly larger and work well, plus cost only about $30, though they have a slightly larger dead band.

Some fry cookers have sensitive enough controls, but many deep fryers designed to primarily run at 375F, lack control sensitivity and have large dead bands at 250F.

Either boil or distill off the alcohol until the liquid is reduced to a pool of oil and all but minor bubbles cease rising at the edges and then pour at least ten volumes of alcohol and wash out the whole pot by swirling it and washing off any resin stuck to the sides.

Using a funnel, pour that liquid into a jar or bottle, seal it, and place that in the freezer.

I usually leave it at least overnight, but have pushed it to a couple hours. The liquid will lose its clarity and become slightly cloudy, primarily from plant waxes flocculating out.

Filter that liquid one more time, and you will have a bell clear extract, that is ready to reduce down one more time.

Place in a suitable container for return to the oil bath. Since you have much less material, a smaller one may be used.

At this point I put them in small stainless cups with their tare engraved on their sides or a Pyrex beaker. The smaller container reduces the surface area that will be coated with oil when I cook it down the last time and knowing the cups tare weight allows me to take it directly from the oil bath and place it on a scale after simply wiping the exterior.

Since I know the tare, I then know the extracted weight, and exactly how much other ingredients to add. Once adding those ingredients, I place the cup back in the oil bath, where I stir it until well mixed and then decant into its final container.

Since the added ingredients include things that lower the cannabis oils viscosity, very little is left as a film in that container.

If I plan to use the oil as is, without adding any other ingredients, I extract it from the container using a pipette, so as to not leave a streak of material in the vessel. After I have extracted all that I can using a pipette, I wash the container and pipette out with hot alcohol, and save the wash for the next run.

Nothing is wasted or left behind.
 

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Gray Wolf

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Hey Gray Wolf, thank you for the great post!
Hope you willn't mind a little remind on "Add some water"-step to be sure that after EtOH washes there is:thank you:

Good point brother Jump!

At brother Jump's suggestion, after the second extraction of frozen cured material, I filled the gallon jar with water while the material was still wet with alcohol and after shaking well, strained and filtered it.

I then boiled off the water and was amazed at how much material was left behind.

It was an interesting red color and appeared to contain a fair amount of wax, in addition to the oil that was in the residual alcohol.

After re-dissolving that extraction in warm ethanol, I placed it in the freezer to coagulate and then filtered it once again, before reducing to oil.

A ton of reddish wax dropped out, but it yielded yet more pristine oil.

To my discredit, it appears that I didn't take pictures and have only done it that one time. The reason I don't do it every time, is that it is a lot of work to clean up after extraction and raw material is more abundant than my available time.

Were that not so, I most assuredly would do it every time and salute brother Jump for comming up with the idea!

My statement that nothing is wasted or left behind requires this qualification.
 
E

el dub

Thanks, Gray Wolf.

One question.....

After the first evap, you are adding back alcohol. Would that amount be at least 10X the volume oil produced? eg: 10 oz alcohol would be added to 1oz oil?

I'm ultimately wondering about the amount of oil lost to the filter gods at different concentrations of oil/alcohol during the second filtration.

Thanks, mon.

lw
 

Gray Wolf

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Thanks, Gray Wolf.

One question.....

After the first evap, you are adding back alcohol. Would that amount be at least 10X the volume oil produced? eg: 10 oz alcohol would be added to 1oz oil?

I'm ultimately wondering about the amount of oil lost to the filter gods at different concentrations of oil/alcohol during the second filtration.

Thanks, mon.

lw

Yes I am adding back ~10 volumes alcohol.

Yes the filter gods must be fed. You can dillute to 100X and waste less filtrate, but it is more work reducing back down.
 

bloyd

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I am a bit confused. Are you saying that qwet oils are voted most flavorful even after decarb? or do you drive off the alcohol differently for oils that will be vaped? Under Vacuum?
 

Gray Wolf

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I am a bit confused. Are you saying that qwet oils are voted most flavorful even after decarb? or do you drive off the alcohol differently for oils that will be vaped? Under Vacuum?

Sorry, I confuse myself sometimes!

May I offer an example?

We periodically present 10 MMJ patient classes, in some of the oil extraction methods. We extract:

1 QWET cured material
2 QWET fresh material
3 QWISO cured material
4 Ethanol reflux
5 Ethanol soxhlet
6 BHO cured
7 BHO fresh

At the end of the full day of hands on running 7 processes simultaneously, we share the product with the students, by vaporizing each extract in its own dedicated clean glass pipe bowl, and they report their impressions.

We also allow the students to taste an acetate and esters, to interest them in the next level of classes.

The reported results of those tests are as follows:

1.0 Most tasty was fresh frozen BHO extraction. The different floral turpenoid flavors soar in all directions and the word most often chosen to describe the flavor was "fresh".

2.0 Next most tasty reported was QWET cured, though by a narrow margin as compared to QWISO cured.

3.0 Interestingly least tasty was QWET of fresh frozen material which was perceived on average to be bland. One description was even soapy.

4.0 BHO cured was reported to have the most hashy flavor and was preferred by some.

5.0 I actually lied when I said that fresh BHO was voted most tasty, it actually ran second, but was first in the extractions.

Cannabis acetate actually got the most marks for flavor, but the test was skewed by some of the testers dropping out after the first couple of tests and only picking up on the last because the remaining testers were so enthusiastic about them.

Personally, I find them all a delight and it is good to be able to switch around. My absolute best four bean soup gets old by at least the third day.
 

cebe11

Member
Excellent thread!
I'm reading lots on extractions and have little experience so be easy on me.

I always prefer to make kief with my bud/trim so have lots of it on hand. I would like to use it to make a tincture with alcohol.

I can only get 76% alcohol vodka - no Everclear here.
How could I modify this procedure to use only kief and vodka?

I was planning to take a couple of grams of kief - heat up 2-3oz of vodka to 250F in oil bath and cook for 30 minutes to reduce liquids and decarb.

Would this be able to be used sublingually? What would the proper ratios be of kief to alcohol?

Thanks!
 

jump117

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250F (121C) - at this temperature vodka quickly boil away.
I think it is better to decarboxylate kief before, and then dissolve it in heated vodka.
 

Gray Wolf

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Excellent thread!
I'm reading lots on extractions and have little experience so be easy on me.

I always prefer to make kief with my bud/trim so have lots of it on hand. I would like to use it to make a tincture with alcohol.

I can only get 76% alcohol vodka - no Everclear here.
How could I modify this procedure to use only kief and vodka?

I was planning to take a couple of grams of kief - heat up 2-3oz of vodka to 250F in oil bath and cook for 30 minutes to reduce liquids and decarb.

Would this be able to be used sublingually? What would the proper ratios be of kief to alcohol?

Thanks!

As Jump notes, you will never get to 250F while there is still alcohol present to boil away. Even with a 250F oil bath, the alcohol mixture will boil in the neighborhood of 172F.

Using more dilute alcohol still works, it just doesn't produce as clean an extraction because it will extract more of the water solubles. There are less water solubles to deal with using kief, vis vis raw plant material.

I reflux boil kief about thirty minutes and have never weighted or measured the amount of alcohol per gram of kief. I simply pour in "enough."

As an arm wave guess, I would say 20 or so times the kief volume, but you can't have too much and you most certainly can have too little.

Here is the first cook on 21 grams of bubble, with the second cook just starting. Looks like I used a half pint of alcohol, plus what ever the material soaked up, since the jar shown is a pint.

PS: If you cook in a glass jar, be very careful what temperature you place it in the hot oil at, lest the jar break.
 

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Gray Wolf

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Sorry, after three tries I gave up on trying to attach this as an edit to the last post. Here is the pile of bubble that was processed in the jar shown above. Sure wish I was more of a computer guru!
 

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cebe11

Member
Thanks!
Makes much more sense with decarbing the kief first - then adding to the alcohol. Throw in reflux boiling and voila I hope to be baked.
Thanks for all the info in this and other threads - its fascinating to me - although I'm daft in the chemistry part.
=cebe
 

StinkyGreen

Member
Grey Wolf, I have a couple questions for you about your QWET method. I tried following your instructions but think I screwed up the very first step and ground my material too fine.

1) In the beginning when you scrub the frangible material through a wire mesh pasta strainer, what size holes should it have? My pasta strainer has holes about the same size as a window screen.

2) What color is the liquid you usually get from a 3 min frozen wash of cured bud with 95% Everclear? Mine was was surprisingly bright green. I did do a 2-step filtering process - it was definitely only a 3 min frozen wash. I used cheesecloth to do the first filtering step, and a coffee filter for the 2nd. Worked well. I wet them both with ethanol before filtering to try to minimize filter loss.

3) When I evaporated the filtered solution (seedling mat + fan), there was a white almost powdery residue on the result. Have you ever seen this? Would the fact that I ground up my material so fine cause me to pick up additional plant material?

Thanks in advance for your advice. And like many others, I also really appreciate all the great info you've shared with others on this forum.

Edit: I decarboxylated the residue at 250F for 27 min and that seemed to eliminate the white powder. Not sure whether it evaporated or melted back into oil or what, but it's gone and the remaining oil looks like it should. So maybe I didn't screw up that badly after all :)
 
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Gray Wolf

A Posse ad Esse. From Possibility to realization.
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Grey Wolf, I have a couple questions for you about your QWET method. I tried following your instructions but think I screwed up the very first step and ground my material too fine.

1) In the beginning when you scrub the frangible material through a wire mesh pasta strainer, what size holes should it have? My pasta strainer has holes about the same size as a window screen.

2) What color is the liquid you usually get from a 3 min frozen wash of cured bud with 95% Everclear? Mine was was surprisingly bright green. I did do a 2-step filtering process - it was definitely only a 3 min frozen wash. I used cheesecloth to do the first filtering step, and a coffee filter for the 2nd. Worked well. I wet them both with ethanol before filtering to try to minimize filter loss.

3) When I evaporated the filtered solution (seedling mat + fan), there was a white almost powdery residue on the result. Have you ever seen this? Would the fact that I ground up my material so fine cause me to pick up additional plant material?

Thanks in advance for your advice. And like many others, I also really appreciate all the great info you've shared with others on this forum.

Edit: I decarboxylated the residue at 250F for 27 min and that seemed to eliminate the white powder. Not sure whether it evaporated or melted back into oil or what, but it's gone and the remaining oil looks like it should. So maybe I didn't screw up that badly after all :)

My liquid is still amber at 3 minutes.

I use a restaurant supply pasta strainer that is probably twice the size of a window screen and has a second, even coarser, backup screen for support.

Thanks for pointing out that needs more clarification!

Another thing that needs clarification is that you can also get the material too dry. It is easier to show than to describe, but when I say "just frangible", it doesn't mean powder dry. Just frangible is the point that the material will break up readily, but still has some moisture content. Freezing will control the remaining water, and if it is too dry, it will break up too readily and add color.

It also depends on the type of material. I pulverize leaf and trim material to get rid of all the stems and give it a uniform texture that will readily load and compact. If I am running straight buds, I usually am running a gallon jar full or less, so I often just coarsely break up the material by hand to about twice or three times the size of joint rolling material.

I haven't noticed white powder, but suspect they were plant waxes. When you store the ethanol solution overnight at 0F, the waxes that coagulate and precipitate out, appear whitish.

The test is always in the sampling! Good to hear the final product turned out well and look forward to hearing the test results!
 

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StinkyGreen

Member
Thanks for the additional info. I'll know better for next time. FWIW, I did put the filtered solution in the freezer overnight, but nothing coagulated out. I notice you do this *after* you've evaporated and re-added ethanol though. Is there something about the additional evaporation/remixing step that causes waxes to precipitate out the second time?

Edit: BTW, I got 2g of great looking (to me) light amber oil out of this. 20% yield. I dissolved it in 30mL of 95% Everclear.

Will post my test results soon :)
 

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