harvest right freeze drier

PDX Dopesmoker · Jan 10, 2018

Easy7 said:
Anyone recall what processed food is like? Ya all get creative with processed ganja. That is a side effect of legalization, marketing, and boredom.

I enjoyed seeing your post closely followed by Patmando22's cold trap suggestion, but I got to tell you that some processed food is really good. Freeze-dried strawberries for instance have a fantastic flavor and a much higher density of that flavor than the original highly perishable fruit product. If you take freeze-dried strawberries and crush them while deeply frozen to dust in a food processor and then sift out the strawberry seeds the flavor density is even higher and you can use the pretty pink powder as very nice flavor additive for whatever you're cooking.
I grok your vibe and am down with it entirely, but sometimes the bored playboys come up with something genuinely worthwhile. The Wright brothers invented the airplane just fucking around looking for a new way to get high after all.

ChaosCatalunya · Jan 10, 2018

WaterFarmFan said:
Thanks for the info. When you say "go quite strong", are you referring to a deep vacuum level? I am curious about vacuum level from my own vacuum oven terpene extraction experiments. Under deep vacuum, there is very little convection heating happening, because there are no gas molecules to bounce around and heat material. Thus, under vacuum there is only radiation and some conduction.

So, I wonder if they are doing deep vacuum during freeze process, which induces sublimation, and then a minimal vacuum level during heating process to encourage convection, which encourages evaporation? Is what I described the default state of the basic harvestright, or would it require programming?

Yes, I believe so, I will try to get some more info from my friend

Lazyman · Jan 12, 2018

Yeah the machine has an external vacuum pump attached. You can set how long to freeze and to vacuum.

It first freezes to -50*F for a few hours, which pushes the water out of the material as solid water ice. To get it to evaporate as a gas (sublimation) it applies a deep vacuum, then heats the trays up 10zF to -40*F, then freezes again and repeats for a day or two, or until no more water remains.

From what I've read about curing, chlorophyll only breaks down in conditions over 55% RH, and if it drops below that mark (too dry) the cure is "broken" and can't be restarted.

I'm still messing with my original jar, some of the smell is coming back a month later, but as I was looking at it as a possible commercial service endeavour, there's no hope yet.

Freeze drying leaves 0% moisture in the flowers, you could easily turn a handful of nugs into a fine dust with your bare hand.

You can add a cold trap, yes. I've seen videos of it being done, even homebrew in fashion, but it's probably far more economical to add the tiny amount of terpenes back by buying them. $600 for a cold trap would buy a shitload of terpenes.

WaterFarmFan · Jan 12, 2018

Thanks for that description. What happens to the water during the cycle?

Patmando22 · Jan 12, 2018

It terns from a solid ice to a gas and gets vacuumed out without ever becoming a liquid

bloyd · Jan 12, 2018

WaterFarmFan said:
Thanks for that description. What happens to the water during the cycle?

Most of the water vapor condenses and freezes to the inner metal drum which stays frozen at -50 f. You can defrost and drain this and your left with a hydrosol, I have tried to separate unsuccessfully with sep funnel. The water vapor that doesn't condenser on the drum goes to the pump oil. It is recommended to filter or change the oil after every dry session. You could put a cold trap in- line but the pump and dryer uses threaded 1 inch fittings so you need to custom make it I've never seen a commercial unit compatible.

The trays on my standard unit have silicone heat mats that are adjustable from 5°F to 150°F, I have tried various temperatures always below 125°F as low as 10°F in the end result is similar, so I think the intense vacuum is the main factor. You can also adjust drying time. I I believe the only difference with the scientific model is it gets a bit colder and can lead link to a computer.

In my mind I figured that it would preserve Terps very well being that the chamber stays at -50°F, but never thought about the fact that the activation energy required to sublimate water is greater than for terpenoids so obviously many of those will go before and with the water.

I could see its usefulness if you're drying pounds of bubble for a commercial market but currently I'm only using it to dry lady boys for pollen.

WaterFarmFan · Jan 12, 2018

Thanks Pat. This is where I am confused. I understand that sublimation happens at cold temperatures under vacuum, but the water vapor still behaves as a gas once it leaves plant material, which makes me believe that it will condense back to liquid/frozen ice on the coldest parts of the freeze drier. If this is happening, then terpenes are also condensing on the chiller element of the freeze drier. If not, then large amounts of water with some terpenes would be constantly contaminating vacuum pump oil?

EDIT - Thanks Bloyd. Answered a lot of my questions.

Patmando22 · Jan 12, 2018

You are right, there is a part in the freezer that gets iced up i think. That would be were most of the lost terps would be. I think it would be hard to recover them from the ice.

Patmando22 · Jan 12, 2018

Im sure you loose terps in a traditional dry of water hash. The difference between the amount of terps lost from the different drying methods is what im most interested in.

WaterFarmFan · Jan 12, 2018

Does the chilling element ever turn off during the heating cycle? Does the vacuum pump stay on during the entire cycle?

Patmando22 · Jan 12, 2018

I do have to say a friend of mine is using the freeze dryer with excellent results with his hash. Would like yo take a batch and do 3 different drys to compare the quality.

bloyd · Jan 13, 2018

WaterFarmFan said:
Does the chilling element ever turn off during the heating cycle? Does the vacuum pump stay on during the entire cycle?

Yes chilling pump stays on while drying otherwise all of your water vapor would go to pump oil causing pump to overfill and spray oil out of handle. Contaminated vac oil will greatly extend dry time.

Vacuum pump kicks on for dry session after freeze session. The default freeze session is 9 hours but can be lowered if you prefreeze. The system is under vacuum and pump runs (very loud and annoying) the entire dry session (when heat mats come on)

bloyd · Jan 13, 2018

Patmando22 said:
I do have to say a friend of mine is using the freeze dryer with excellent results with his hash. Would like yo take a batch and do 3 different drys to compare the quality.

Excellent results that you've seen or consumed? I agree it makes things visually appealing (neon green buds/white hash), but the loss in flavor, aroma, greasiness etc made the looks mute for me.

I'm small time and have donated enough buds and hash to my machine At different settings to determine its not for me. If someone wants to share their settings I would give it another chance but for now I consider it an expensive learning lesson.

WaterFarmFan · Jan 13, 2018

bloyd said:
Yes chilling pump stays on while drying otherwise all of your water vapor would go to pump oil causing pump to overfill and spray oil out of handle. Contaminated vac oil will greatly extend dry time.

Vacuum pump kicks on for dry session after freeze session. The default freeze session is 9 hours but can be lowered if you prefreeze. The system is under vacuum and pump runs (very loud and annoying) the entire dry session (when heat mats come on)

Makes more sense now. This seems like a difficult setup to cold trap terpenes while drying material, as most would condense inside. Also, unless you had a leak in the system, there would be minimal flow between the pump and drier, other than burping and the change in condensation/volatilization pressures.

You could possibly create a process with cold traps at the end of the session. Something like this (if possible):

Remove all material from trays.
Heat trays to maximum temp.
Turn off heating/cooling on drier.
Pour boiling water into base of system.
Immediately shut door and pull full vacuum.
Defrost over X hours and collect terpenes in traps.

Ideally, you would want to disable the chilling pump and only heat under the defrost process. You could cheat this by adding an additional stainless container with boiling water, which under full vacuum should produce steam and greatly help to warm chamber to re-volatilize terpenes for collection.

Seems like a pain the ass, but the alternative would be some kind of low temp distilled water pressure wash of the chamber followed by the immediate collection. You probably tried something similar. Terpenes fucking love to stick to ANYTHING, so I always try to minimize surface area and do multiple rinses with progressively warmer distilled water, but always immediately seal with glass stoppers using glass flasks. Also found a minimum of 12 hours at ~2c to get a decent separation in funnel.

WaterFarmFan · Jan 13, 2018

As for getting too dry. I assume you are using a high quality, low micron vacuum pump like an Edwards? Have you tried the process with a dumpy hvac pump? You could use motorized or manual ball valves with some tees and switch back and forth between high and low micron pumps during the process, and turn off the vacuum independent of the system. You might find that the terpenes are lost in the heating cycle and play with higher vacuum levels to counter.

bloyd · Jan 13, 2018

WaterFarmFan said:
Makes more sense now. This seems like a difficult setup to cold trap terpenes while drying material, as most would condense inside. Also, unless you had a leak in the system, there would be minimal flow between the pump and drier, other than burping and the change in condensation/volatilization pressures.

You could possibly create a process with cold traps at the end of the session. Something like this (if possible):

Remove all material from trays.
Heat trays to maximum temp.
Turn off heating/cooling on drier.
Pour boiling water into base of system.
Immediately shut door and pull full vacuum.
Defrost over X hours and collect terpenes in traps.

Ideally, you would want to disable the chilling pump and only heat under the defrost process. You could cheat this by adding an additional stainless container with boiling water, which under full vacuum should produce steam and greatly help to warm chamber to re-volatilize terpenes for collection.

Seems like a pain the ass, but the alternative would be some kind of low temp distilled water pressure wash of the chamber followed by the immediate collection. You probably tried something similar. Terpenes fucking love to stick to ANYTHING, so I always try to minimize surface area and do multiple rinses with progressively warmer distilled water, but always immediately seal with glass stoppers using glass flasks. Also found a minimum of 12 hours at ~2c to get a decent separation in funnel.

The unit actually has a defrost feature where it melts the ice that's condensed. I thought the same to defrost the unit under vacuum
with cold trap in line for terps. Problem being the funny threads would require custom cold trap. Haven't put effort into purchasing/building that as i didn't like results.

I have in the past just let the ice block melt under room temperatures and collected the condensate in a container from the drain valve. I am sure many of the terpenes are just being lost to atmosphere in the process but the collected hydrosol definitely holds a lot of them but also smells very green.

I am definitely intrigued and I am sure some are probably collecting and purifying terps. If I find a good way to collect/purify the terps I would like to duplicate your method of fresh terp extraction followed by subzero ethanol extraction for pens.

bloyd · Jan 13, 2018

WaterFarmFan said:
As for getting too dry. I assume you are using a high quality, low micron vacuum pump like an Edwards? Have you tried the process with a dumpy hvac pump? You could use motorized or manual ball valves with some tees and switch back and forth between high and low micron pumps during the process, and turn off the vacuum independent of the system. You might find that the terpenes are lost in the heating cycle and play with higher vacuum levels to counter.

I have only used the pump that comes with it. It is a 6cfm jb eliminator. I don't know if it's good or bad my pump knowledge is low.

To counter getting to dry I have played with stopping the machine before it completes b/c it has a sensor that senses moisture and will dry herbs bone dry if you allow it to complete dry cycle. Problem there is its tough to gauge dryness if frozen.

WaterFarmFan · Jan 13, 2018

bloyd said:
The unit actually has a defrost feature where it melts the ice that's condensed. I thought the same to defrost the unit under vacuum
with cold trap in line for terps. Problem being the funny threads would require custom cold trap. Haven't put effort into purchasing/building that as i didn't like results.

I have in the past just let the ice block melt under room temperatures and collected the condensate in a container from the drain valve. I am sure many of the terpenes are just being lost to atmosphere in the process but the collected hydrosol definitely holds a lot of them but also smells very green.

I am definitely intrigued and I am sure some are probably collecting and purifying terps. If I find a good way to collect/purify the terps I would like to duplicate your method of fresh terp extraction followed by subzero ethanol extraction for pens.

Here is another thing that I am trying to wrap my head around. Terpenes are in trichomes, which contain a mixture of liquid and some solid compounds wrapped in a waxy shell. Water is certainly in the trichomes as well. Do you think that the very long initial freeze could be the primary driver of terp lose in your process? How many times does the system freeze/thaw per session?

I freeze material with ln2 a few times, including a complete soak submerged in cannisters for 5-10 minutes, but it is only below freezing for 30-45 min. My oven process does evaporation much better than sublimation, but this has me thinking that I could process (pulverize) with ln2, and then place separated (trichomes in one and flower material in other) material in dry ice chest for 8-12 hours prior to beginning terpene extraction and subsequent drying. Just freezing with ln2 does not cause the trichomes to rupture, so would a much longer freeze time (with higher temps vs ln2 for longer) have a different effect?

Another thing to remember is that terpenes come in all forms of compounds and some have different characteristics other than a clear oil. As such, they condense at very different points. I keep adding more cold trap stages with dry ice/etoh and keep finding more terpenes. My latest addition is a new final stage with twin 400mm Dimroth condensers that are interconnected.

When you are trying to "catch smells", you have to go to some pretty crazy lengths...

PDX Dopesmoker · Jan 14, 2018

Patmando22 said:
Im sure you loose terps in a traditional dry of water hash. The difference between the amount of terps lost from the different drying methods is what im most interested in.

I always felt like the flavor loss making water hash had more to do with what the water takes out of the hash rather than what is lost during drying after the hash is all out of the bath. On some strains the water really smells fantastic. Bubblegum hashwater smells just like the first few chews of a stick of pink bubblegum.

Do the people who press the freeze dried material for rosin ever add any moisture back before pressing?

Patmando22 · Jan 14, 2018

Iv herd of people pulling the hash out of the freeze drier early to leave a lil moisture in the hash for pressing

harvest right freeze drier

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