[WaterFarmFan]

Hello all. Been doing a lot of testing with making extracts with ethanol extraction. I pre-process prime cured flower by making dry ice hash using 190 screen bubble bag. I use 2x 5 gallon buckets and shake for 3-4 minutes in first bucket, and then another 3-4 minutes in the 2nd. I then immediately dump the bubble bag material in a tray and remove all dry ice chunks which draw in moisture.

I now have 3 grades of material and place each in a labeled ziplock. The logic of doing this first step is to dry the material further without adding heat, and second to use less ethanol. I often do several pounds in 6-8 ounce runs, and it is basically a closed system that has no reduction in yield. Bubble bag is caked with kief at the very end, but I just place this bag in a traditional ice water bubble bags and get some nice bubble hash for me.

I then use a modified medical transport cooler as a sink with a 10x10x2 slab of dry ice to cool all material to around -40 F. The 10x10 holds 5x 500ml beakers, which is usually is 2x 1st pass kief, 1x 2nd pass kief & 2x bag leftover - all from the same strain. I have a second dry ice storage chest that I use to pre-cool the ethanol to -40 F/-50 F.

I follow many things from Skunk Pharm Research, but my filtering process is a little different since I now have fine kief and pulverized flower material, which takes much longer to filter. After testing 190, I only use 200 proof Extractohol to avoid contaminant pickup, as ethanol is exposed to material for 30-45 minutes total. I pour the -50F ethanol completely over the pre-cooled (20-30 minutes) material in all beakers and let sit for 10-15 minutes stirring a few times.

I use a 1000ml buchner funnel with 110mm Whatman #1 filters connected to BVV 1.5 Gallon Cold Trap and 3cfm vacuum pump. I installed a series of ball valves that let me isolate and throttle vaccum. I made what could be called a removable thermal diaper using radiant barrier material and foil tape that completely covers the sides and bottom of buchner funnel with about 3/4" gap around all sides. I then place about 1/2 pound of dry ice pellets around the outside of the funnel and cover it with another thermal lid made from radiant barrier. After cooling for 10-15 minutes, the glass frit and most of funnel is -30F - -40F, and it is ready to go.

I then place a fresh #1 filter and pour a small amount of chilled ethanol over filter and turn on vacuum to prime. I throttle vacuum (between pump and cold trap) so that no liquid is sucked into vacuum line from funnel and then completely pour the contents from 1st pass kief beakers into the filter. The fine kief quickly clogs the filter and requires an increase in vacuum (to about 75%) to maintain a nice steady filter pour. Depending on material - 6 ounces for this example, it takes about 5-7 minutes to filter 500ml from initial beaker soaking. After the material on filter dries out slightly, I will pour another 200-300ml chilled ethanol to maximize extraction.

Now, I pour the ~700ml of filtered ethanol into a clean beaker and set aside. After reattaching funnel to flask, I bring back to near full vacuum and pour the 2nd pass kief solution on top of the 1st pass still in the filter. This takes ~10 minutes to fully filter, after which I add the final 2 beakers of bag material solution. Bag material takes about 10-15 minutes to filter. 2nd pass and bag material stay in same flask. After fully filtering, I add another 200-300ml chilled ethanol to maximize extraction. At this point, the kief/bag material in the funnel is still at -20 - -30F, and depending on amount of starting material, it is a solid 1 1/2"-2" thick above filter pad.

I now have 2 grades of extract laden ethanol, which I can process separately or just add together for full body. The 1st grade is always deep amber, but the 2nd grade does pick up a very small shade of pale green, but after 30-60 minutes at room temperature, or immediately upon heating, all green goes away and a deeper amber than 1st remains. Both are crystal clear with no clouds. I then use a heating and stirring mantle and distillation apparatus to separate ethanol. Once ~85% of ethanol is evaporated, I collect material in small beaker and use 0.22um syringe filters. Solution goes from syringe directly into 120mm glass petri dishes, which have been marked and pre-weighed, and into AI 5-wall vacuum oven. I try to estimate 5-6 grams of shatter per petri dish.

Now, this brings me to the heart of my post. My first few tests using the system above produced the most rock hard shatter that I found nearly impossible to fully purge (at temps below 130). The 200 proof ethanol creates a thick film that bubbles have a very difficult time popping. I did some small tests that took temps of 160 under full vacuum (29.5) to purge. This is obviously not acceptable for creating vapable extracts.

I did the exact same steps above using 190 proof Everclear, and it does pick up a bit more green on 2nd/bag run, but it also picks up a cloudy element and other contaminants - clearly not acceptable either. However, I found that 190 processed material was easy to purge using a temp ramp from 110 to 125 over a few hours. It produced a much runnier extract far from shatter.

So... For my last test, I did my 200 proof process through distillation, but right before the 0.22um step, I poured a small amount of 190 Everclear in the solution. I used 40ml of Everclear for what I estimated would be 40 grams of shatter. 190 is 5% water, so 40 x .05 = 2ml of water added into solution. It turned out that this worked fantastic. It purged easily and created a nice hard taffy shatter.

However, my last batches of fully purged shatter have had little taste when I dab. Great and powerful high, but not much taste. I make both oral meds and vape products, and I have averaged about 25-27% shatter using some high quality flowers from Bodhi strains with this process.

I felt in necessary to better explain my process first, but my questions are the following:

1.) Am I even extracting all the terps, given the temps and fact that 200 proof ethanol has no water for water soluble terps?

2.) Is there another step, perhaps adding some 190 at the end of filtering when temps are slightly warmer but still below 0F to get more terps? Or can I process the left over material in a different manner solely for terp extract to add back?

3.) How careful about temps should I be during distillation/evaporation process to preserve terps? I have an analog heat/stir mantle, but it is connected to digital temperature controller and probe that can cycle it on and off. Should I keep my mantle temps below 110 on full vac?

4.) How long are people vacuum purging? 1 hours? 2 hours? 6 hours? I have been doing 30-45 at 110, mild stir to break film, 30 minutes at 115, mild stir, 30 minutes at 120, mild stir and then however long it takes at 125 to completely thin film.

I am really interested in any feedback that you might have about this process and terp preservation!!! Thanks all!!!

WFF

[WaterFarmFan]

Another more generic question would be, are terpenes located in the trichomes, vegetative matter, or both?

WFF

[WaterFarmFan]

Any thoughts on doing a steam distillation on the material left in the filter? Would the residual ethanol in material affect steam distillation process?

Reading continues...

WFF

[self]

great stuff WFF, wish i could help you out, but im here to learn.

[WaterFarmFan]

Originally Posted by self

great stuff WFF, wish i could help you out, but im here to learn.

Me too! I have advanced quite a bit in my understanding, but there is still a long way to go. Quite a few things wrong in the post above and I have changed many steps as well.

To answer my basic question above, I am extracting most of the terpenes with the etoh but losing many of them during purge. The trick to minimizing terpene lose (which is inevitable) is to use the lowest possible temperatures during distillation and final purge.

Now, I am using liquid nitrogen instead of dry ice to process material and added a new step of vacuum oven terpene extraction at the very beginning. So, I extract terpenes without damaging material, do a low temp qwet, purge & then add back true cannabis terpenes at the end. I am still refining my terpene extraction variables and process, but I will create a new thread with complete details in a short period of time.

WFF

[Gray Wolf]

Originally Posted by WaterFarmFan

Hello all. Been doing a lot of testing with making extracts with ethanol extraction. I pre-process prime cured flower by making dry ice hash using 190 screen bubble bag. I use 2x 5 gallon buckets and shake for 3-4 minutes in first bucket, and then another 3-4 minutes in the 2nd. I then immediately dump the bubble bag material in a tray and remove all dry ice chunks which draw in moisture.

I now have 3 grades of material and place each in a labeled ziplock. The logic of doing this first step is to dry the material further without adding heat, and second to use less ethanol. I often do several pounds in 6-8 ounce runs, and it is basically a closed system that has no reduction in yield. Bubble bag is caked with kief at the very end, but I just place this bag in a traditional ice water bubble bags and get some nice bubble hash for me.

I then use a modified medical transport cooler as a sink with a 10x10x2 slab of dry ice to cool all material to around -40 F. The 10x10 holds 5x 500ml beakers, which is usually is 2x 1st pass kief, 1x 2nd pass kief & 2x bag leftover - all from the same strain. I have a second dry ice storage chest that I use to pre-cool the ethanol to -40 F/-50 F.

I follow many things from Skunk Pharm Research, but my filtering process is a little different since I now have fine kief and pulverized flower material, which takes much longer to filter. After testing 190, I only use 200 proof Extractohol to avoid contaminant pickup, as ethanol is exposed to material for 30-45 minutes total. I pour the -50F ethanol completely over the pre-cooled (20-30 minutes) material in all beakers and let sit for 10-15 minutes stirring a few times.

I use a 1000ml buchner funnel with 110mm Whatman #1 filters connected to BVV 1.5 Gallon Cold Trap and 3cfm vacuum pump. I installed a series of ball valves that let me isolate and throttle vaccum. I made what could be called a removable thermal diaper using radiant barrier material and foil tape that completely covers the sides and bottom of buchner funnel with about 3/4" gap around all sides. I then place about 1/2 pound of dry ice pellets around the outside of the funnel and cover it with another thermal lid made from radiant barrier. After cooling for 10-15 minutes, the glass frit and most of funnel is -30F - -40F, and it is ready to go.

I then place a fresh #1 filter and pour a small amount of chilled ethanol over filter and turn on vacuum to prime. I throttle vacuum (between pump and cold trap) so that no liquid is sucked into vacuum line from funnel and then completely pour the contents from 1st pass kief beakers into the filter. The fine kief quickly clogs the filter and requires an increase in vacuum (to about 75%) to maintain a nice steady filter pour. Depending on material - 6 ounces for this example, it takes about 5-7 minutes to filter 500ml from initial beaker soaking. After the material on filter dries out slightly, I will pour another 200-300ml chilled ethanol to maximize extraction.

Now, I pour the ~700ml of filtered ethanol into a clean beaker and set aside. After reattaching funnel to flask, I bring back to near full vacuum and pour the 2nd pass kief solution on top of the 1st pass still in the filter. This takes ~10 minutes to fully filter, after which I add the final 2 beakers of bag material solution. Bag material takes about 10-15 minutes to filter. 2nd pass and bag material stay in same flask. After fully filtering, I add another 200-300ml chilled ethanol to maximize extraction. At this point, the kief/bag material in the funnel is still at -20 - -30F, and depending on amount of starting material, it is a solid 1 1/2"-2" thick above filter pad.

I now have 2 grades of extract laden ethanol, which I can process separately or just add together for full body. The 1st grade is always deep amber, but the 2nd grade does pick up a very small shade of pale green, but after 30-60 minutes at room temperature, or immediately upon heating, all green goes away and a deeper amber than 1st remains. Both are crystal clear with no clouds. I then use a heating and stirring mantle and distillation apparatus to separate ethanol. Once ~85% of ethanol is evaporated, I collect material in small beaker and use 0.22um syringe filters. Solution goes from syringe directly into 120mm glass petri dishes, which have been marked and pre-weighed, and into AI 5-wall vacuum oven. I try to estimate 5-6 grams of shatter per petri dish.

Now, this brings me to the heart of my post. My first few tests using the system above produced the most rock hard shatter that I found nearly impossible to fully purge (at temps below 130). The 200 proof ethanol creates a thick film that bubbles have a very difficult time popping. I did some small tests that took temps of 160 under full vacuum (29.5) to purge. This is obviously not acceptable for creating vapable extracts.

I did the exact same steps above using 190 proof Everclear, and it does pick up a bit more green on 2nd/bag run, but it also picks up a cloudy element and other contaminants - clearly not acceptable either. However, I found that 190 processed material was easy to purge using a temp ramp from 110 to 125 over a few hours. It produced a much runnier extract far from shatter.

So... For my last test, I did my 200 proof process through distillation, but right before the 0.22um step, I poured a small amount of 190 Everclear in the solution. I used 40ml of Everclear for what I estimated would be 40 grams of shatter. 190 is 5% water, so 40 x .05 = 2ml of water added into solution. It turned out that this worked fantastic. It purged easily and created a nice hard taffy shatter.

However, my last batches of fully purged shatter have had little taste when I dab. Great and powerful high, but not much taste. I make both oral meds and vape products, and I have averaged about 25-27% shatter using some high quality flowers from Bodhi strains with this process.

I felt in necessary to better explain my process first, but my questions are the following:

1.) Am I even extracting all the terps, given the temps and fact that 200 proof ethanol has no water for water soluble terps?

The mono and sesquiterpenes are readily soluble in ethanol and not very soluble in water, but the C-15 flavonoids are water soluble.

2.) Is there another step, perhaps adding some 190 at the end of filtering when temps are slightly warmer but still below 0F to get more terps? Or can I process the left over material in a different manner solely for terp extract to add back?

There are two issues. One is that many of the monoterpenes have high vapor pressure, which is why they can stink up a room through double baggies at ambient temperatures. Even low heat elevates their evaporation rates.

The second is that the terpenes and ethanol love each other enough to combine into a gin during distillation. Smell and taste the recovered alcohol afterwards, and you'll see what I mean.

3.) How careful about temps should I be during distillation/evaporation process to preserve terps? I have an analog heat/stir mantle, but it is connected to digital temperature controller and probe that can cycle it on and off. Should I keep my mantle temps below 110 on full vac?

I've had the best luck preserving monoterpenes at 125F.

4.) How long are people vacuum purging? 1 hours? 2 hours? 6 hours? I have been doing 30-45 at 110, mild stir to break film, 30 minutes at 115, mild stir, 30 minutes at 120, mild stir and then however long it takes at 125 to completely thin film.

I am really interested in any feedback that you might have about this process and terp preservation!!! Thanks all!!!

WFF

See answers in blue.

First question is always why is this trip necessary?? What is it about brittle material that is special other than appearance?

The monoterpenes are alcohols, ethers, aldehydes, ketones, and esters, which act as a solvent to the C-22 diterpenoids making the mateial brittle. The more terpenes, the closer to snap and pull the material becomes.

I like marveling at light colored bell clear gem quality shatter, but visual appearance is secondary to aroma, taste, which are secondary to performance.

Cooking it longer under more heat and vacuum will remove more of the terpenes, but also have the effect of decarboxylation, which also makes the material soft.

Looking for solutions, how thin are the films you are purging from?

You can speed up purging some by bumping the pressure levels when the huge bubbles form and don't break.

I pop a shot of N2 back fill into the oven, which collapses the bubbles, and then I resume vacuum again.

Time and airing in a thin film will also harden up soft material if it is simply retained solvent or water. Set it out to cool and air after purging, with a towel covering it to keep dust (and/or pet hairs) out.

[WaterFarmFan]

Originally Posted by Gray Wolf

See answers in blue.

First question is always why is this trip necessary?? What is it about brittle material that is special other than appearance?

The monoterpenes are alcohols, ethers, aldehydes, ketones, and esters, which act as a solvent to the C-22 diterpenoids making the mateial brittle. The more terpenes, the closer to snap and pull the material becomes.

I like marveling at light colored bell clear gem quality shatter, but visual appearance is secondary to aroma, taste, which are secondary to performance.

Cooking it longer under more heat and vacuum will remove more of the terpenes, but also have the effect of decarboxylation, which also makes the material soft.

Looking for solutions, how thin are the films you are purging from?

You can speed up purging some by bumping the pressure levels when the huge bubbles form and don't break.

I pop a shot of N2 back fill into the oven, which collapses the bubbles, and then I resume vacuum again.

Time and airing in a thin film will also harden up soft material if it is simply retained solvent or water. Set it out to cool and air after purging, with a towel covering it to keep dust (and/or pet hairs) out.

Really appreciate you sharing your knowledge. This is an older post and I have a lot better handle on my distillation and purge variables. One thing that I noted is that the longer that I let my etoh solution be exposed to open air, the more runny it seems the shatter would become, as I think it is picking up water via humidity, which is low in my space. In my early attempts, I would stop distillation a bit too early (before the bumpy syrup stage) and let it sit out for a day or so to thicken up before purge. However, I found much better results just pushing through the entire process (filter to purge) in a single session.

As for the thin films, I have gone through a range of methods. I started using large glass petri dishes with covers, but I found it a pain to clean and prep these for multiple runs. I tried glass pie pans, but it still seemed to not utilize the surface area of my vacuum oven. So, I am now just using silicone mats and make a roughly 9" diameter film, which usually comes out to around 25-30 grams of finished shatter. Roughly 64 square inches is around .4-.45 grams of shatter per square inch. I do not stir any more, but once the patty has mostly thin filmed, I fold the silicone mat in half and squish the sides together and then pull apart and place back in the oven for one last purge. It seems to pancake up after this but settles to a flawless thin film.

I recently setup n2 backfill on my oven, and will have to try the burping next time. How big of a burp are you talking about in terms of mm Hg? I assume that you would shut off vacuum valve before burp, but if at 29.5 Hg, would you backfill to 28, 20 or lower?

Another question on purging would be about a temperature ramp versus static temperature. Is there any advantage or disadvantage to these techniques? I have been ramping starting at 85-90F with full vacuum, with the thought being that it will splatter less, which is it largely does, but I think that this same effect could be had with higher static temperature (120-125F) and ramping the vacuum level over a period of time.

Thanks as always!

WFF

[coldcanna]

Bump for an interesting thread. Do you folks find ethanol extracts to be LESS terpy than butane or co2?

[coldcanna]

From what I have been seeing, many of the monoterps form azeotropic bonds with the ethanol molecules. Is there a way to recapture them, if distillation wont work? Perhaps for the highest quality etoh we should steam distill terps first?

[WaterFarmFan]

Originally Posted by coldcanna

From what I have been seeing, many of the monoterps form azeotropic bonds with the ethanol molecules. Is there a way to recapture them, if distillation wont work? Perhaps for the highest quality etoh we should steam distill terps first?

Interesting! I basically came to the conclusion that if you really want to keep a complete terpene profile, then you need to extract as much as possible prior to using etoh. Problem with steaming is that it will saturate the material with water. Perhaps with it could be dried efficiently after with a freeze drier, but I think dry Nitrogen steaming is far more viable for use with ethanol later.